• 创建文件系统实战篇


                创建文件系统实战篇

                                  作者:尹正杰 

    版权声明:原创作品,谢绝转载!否则将追究法律责任。

     

    一.EXT系列文件系统专用管理工具-mkfs

    1>.查看mkfs命令

    [root@yinzhengjie.com ~]# mkfs              #想要查看更详细的信息可参考"man mkfs"帮助信息
    Usage:
     mkfs [options] [-t <type>] [fs-options] <device> [<size>]
    
    Options:
     -t, --type=<type>  filesystem type; when unspecified, ext2 is used
         fs-options     parameters for the real filesystem builder
         <device>       path to the device to be used
         <size>         number of blocks to be used on the device
     -V, --verbose      explain what is being done;
                          specifying -V more than once will cause a dry-run
     -V, --version      display version information and exit;
                          -V as --version must be the only option
     -h, --help         display this help text and exit
    
    For more information see mkfs(8).
    [root@yinzhengjie.com ~]# 

    2>.使用mkfs命令创建指定类型的文件系统

    [root@yinzhengjie.com ~]# lsblk /dev/sdb
    NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
    sdb      8:16   0  600G  0 disk 
    ├─sdb1   8:17   0  100G  0 part 
    ├─sdb2   8:18   0  200G  0 part 
    ├─sdb3   8:19   0    1K  0 part 
    ├─sdb5   8:21   0  100G  0 part 
    └─sdb6   8:22   0   80G  0 part 
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# lsblk /dev/sdb
    [root@yinzhengjie.com ~]# mkfs -t ext3 /dev/sdb2 
    mke2fs 1.42.9 (28-Dec-2013)
    Filesystem label=
    OS type: Linux
    Block size=4096 (log=2)
    Fragment size=4096 (log=2)
    Stride=0 blocks, Stripe width=0 blocks
    13107200 inodes, 52428800 blocks
    2621440 blocks (5.00%) reserved for the super user
    First data block=0
    Maximum filesystem blocks=4294967296
    1600 block groups
    32768 blocks per group, 32768 fragments per group
    8192 inodes per group
    Superblock backups stored on blocks: 
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 
        4096000, 7962624, 11239424, 20480000, 23887872
    
    Allocating group tables: done                            
    Writing inode tables: done                            
    Creating journal (32768 blocks): done
    Writing superblocks and filesystem accounting information: done     
    
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# mkfs -t ext3 /dev/sdb2       #对/dev/sdb2分区进行格式化操作,指定文件系统类型为"EXT3"
    [root@yinzhengjie.com ~]# blkid /dev/sdb2
    /dev/sdb2: UUID="75c5448c-1c6f-4f5e-a044-209d5b8b8f4a" SEC_TYPE="ext2" TYPE="ext3" 
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# blkid /dev/sdb2            #查看/dev/sdb2分区的文件系统类型

    二.EXT系列文件系统专用管理工具-mke2fs

    1>.mke2fs概述

      mke2fs是ext系列文件系统专用管理工具,其常用参数如下:
        -t {ext2|ext3|ext4}:
          指定文件系统类型,默认创建的是ext2文件系统类型,而ext2的文件系统基本上被淘汰了,因为它不支持日志功能。     
    -b {1024|2048|4096}:
          指定块大小     
    -L ‘LABEL’:
          设置卷标     
    -j:
          相当于"-t ext3",注意,这几个命令是等效的"mkfs.ext3 = mkfs -t ext3 = mke2fs -j = mke2fs -t ext3",生产环境推荐大家使用“mkfs.文件系统类型”的方式创建文件系统,比如"mkfs.xfs"     -i:
          为数据空间中每多少个字节创建一个inode;不应该小于block大小     
    -N:
          指定分区中创建多少个inode     
    -I:
          一个inode记录占用的磁盘空间大小,128---4096     -m:
          为管理人员预留磁盘空间占总空间的百分比,默认5%,在特定场景下需要可以调小,比如"0.1%"     -O FEATURE[,...]:
          启用指定特性     
    -O ^FEATURE:
          关闭指定特性
    [root@yinzhengjie.com ~]# mke2fs 
    Usage: mke2fs [-c|-l filename] [-b block-size] [-C cluster-size]
        [-i bytes-per-inode] [-I inode-size] [-J journal-options]
        [-G flex-group-size] [-N number-of-inodes]
        [-m reserved-blocks-percentage] [-o creator-os]
        [-g blocks-per-group] [-L volume-label] [-M last-mounted-directory]
        [-O feature[,...]] [-r fs-revision] [-E extended-option[,...]]
        [-t fs-type] [-T usage-type ] [-U UUID] [-jnqvDFKSV] device [blocks-count]
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# mke2fs                #想要查看更详细的文档可参考"man mke2fs"信息

    2>.mke2fs默认创建的是ext2文件系统类型

    [root@yinzhengjie.com ~]# lsblk  /dev/sdb
    NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
    sdb      8:16   0  600G  0 disk 
    ├─sdb1   8:17   0  100G  0 part 
    ├─sdb2   8:18   0  200G  0 part 
    ├─sdb3   8:19   0    1K  0 part 
    ├─sdb5   8:21   0  100G  0 part 
    └─sdb6   8:22   0   80G  0 part 
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# lsblk /dev/sdb
    [root@yinzhengjie.com ~]# mke2fs /dev/sdb1 
    mke2fs 1.42.9 (28-Dec-2013)
    Filesystem label=
    OS type: Linux
    Block size=4096 (log=2)
    Fragment size=4096 (log=2)
    Stride=0 blocks, Stripe width=0 blocks
    6553600 inodes, 26214400 blocks
    1310720 blocks (5.00%) reserved for the super user
    First data block=0
    Maximum filesystem blocks=4294967296
    800 block groups
    32768 blocks per group, 32768 fragments per group
    8192 inodes per group
    Superblock backups stored on blocks: 
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 
        4096000, 7962624, 11239424, 20480000, 23887872
    
    Allocating group tables: done                            
    Writing inode tables: done                            
    Writing superblocks and filesystem accounting information: done   
    
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# mke2fs /dev/sdb1          #我们在使用mke2fs时没有使用"-t"选项指定文件系统类型,默认会帮咱们格式化为"EXT2"类型
    [root@yinzhengjie.com ~]# blkid /dev/sdb1 
    /dev/sdb1: UUID="d5819b04-a9c3-4a10-a09c-ed1284c36658" TYPE="ext2" 
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# blkid /dev/sdb1          #查看该分区的文件系统类型

    3>.创建文件系统时自定义块(block)大小

    [root@yinzhengjie.com ~]# lsblk  /dev/sdb
    NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
    sdb      8:16   0  600G  0 disk 
    ├─sdb1   8:17   0  100G  0 part 
    ├─sdb2   8:18   0  200G  0 part 
    ├─sdb3   8:19   0    1K  0 part 
    ├─sdb5   8:21   0  100G  0 part 
    └─sdb6   8:22   0   80G  0 part 
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# lsblk /dev/sdb
    [root@yinzhengjie.com ~]# mkfs.ext4 -b 1024 /dev/sdb5
    mke2fs 1.42.9 (28-Dec-2013)
    Filesystem label=
    OS type: Linux
    Block size=1024 (log=0)
    Fragment size=1024 (log=0)
    Stride=0 blocks, Stripe width=0 blocks
    6553600 inodes, 104857600 blocks
    5242880 blocks (5.00%) reserved for the super user
    First data block=1
    Maximum filesystem blocks=138412032
    12800 block groups
    8192 blocks per group, 8192 fragments per group
    512 inodes per group
    Superblock backups stored on blocks: 
        8193, 24577, 40961, 57345, 73729, 204801, 221185, 401409, 663553, 
        1024001, 1990657, 2809857, 5120001, 5971969, 17915905, 19668993, 
        25600001, 53747713
    
    Allocating group tables: done                            
    Writing inode tables: done                            
    Creating journal (32768 blocks): done
    Writing superblocks and filesystem accounting information: done       
    
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# mkfs.ext4 -b 1024 /dev/sdb5      #创建EXT4文件系统时自定义块大小为1024
    [root@yinzhengjie.com ~]# blkid /dev/sdb5
    /dev/sdb5: UUID="d65349e8-3c72-4cc3-a7f4-406cfa2c7d29" TYPE="ext4" 
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# blkid /dev/sdb5
    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb5 
    tune2fs 1.42.9 (28-Dec-2013)
    Filesystem volume name:   <none>
    Last mounted on:          <not available>
    Filesystem UUID:          d65349e8-3c72-4cc3-a7f4-406cfa2c7d29
    Filesystem magic number:  0xEF53
    Filesystem revision #:    1 (dynamic)
    Filesystem features:      has_journal ext_attr resize_inode dir_index filetype extent 64bit flex_bg sparse_super huge_file uninit_bg dir_nlink extra_isize
    Filesystem flags:         signed_directory_hash 
    Default mount options:    user_xattr acl
    Filesystem state:         clean
    Errors behavior:          Continue
    Filesystem OS type:       Linux
    Inode count:              6553600
    Block count:              104857600
    Reserved block count:     5242880
    Free blocks:              103140734
    Free inodes:              6553589
    First block:              1
    Block size:               1024
    Fragment size:            1024
    Group descriptor size:    64
    Reserved GDT blocks:      256
    Blocks per group:         8192
    Fragments per group:      8192
    Inodes per group:         512
    Inode blocks per group:   128
    Flex block group size:    16
    Filesystem created:       Wed May 27 06:01:07 2020
    Last mount time:          n/a
    Last write time:          Wed May 27 06:01:08 2020
    Mount count:              0
    Maximum mount count:      -1
    Last checked:             Wed May 27 06:01:07 2020
    Check interval:           0 (<none>)
    Lifetime writes:          34 MB
    Reserved blocks uid:      0 (user root)
    Reserved blocks gid:      0 (group root)
    First inode:              11
    Inode size:              256
    Required extra isize:     28
    Desired extra isize:      28
    Journal inode:            8
    Default directory hash:   half_md4
    Directory Hash Seed:      7205ff80-a245-4335-b2f3-15c1eebf75e8
    Journal backup:           inode blocks
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb5          #查看块大小为1024

    4>.指定预留空间的百分比

    [root@yinzhengjie.com ~]# mkfs.ext4 -b 1024 -m 0.1 /dev/sdb5
    mke2fs 1.42.9 (28-Dec-2013)
    Filesystem label=
    OS type: Linux
    Block size=1024 (log=0)
    Fragment size=1024 (log=0)
    Stride=0 blocks, Stripe width=0 blocks
    6553600 inodes, 104857600 blocks
    104857 blocks (0.10%) reserved for the super user
    First data block=1
    Maximum filesystem blocks=138412032
    12800 block groups
    8192 blocks per group, 8192 fragments per group
    512 inodes per group
    Superblock backups stored on blocks: 
        8193, 24577, 40961, 57345, 73729, 204801, 221185, 401409, 663553, 
        1024001, 1990657, 2809857, 5120001, 5971969, 17915905, 19668993, 
        25600001, 53747713
    
    Allocating group tables: done                            
    Writing inode tables: done                            
    Creating journal (32768 blocks): done
    Writing superblocks and filesystem accounting information: done       
    
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# mkfs.ext4 -b 1024 -m 0.1 /dev/sdb5    #指定块大小为1024.并指定预留的空间为0.1%
    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb5 
    tune2fs 1.42.9 (28-Dec-2013)
    Filesystem volume name:   <none>
    Last mounted on:          <not available>
    Filesystem UUID:          0e1581cf-51a9-4f5a-b1ad-635ac3364578
    Filesystem magic number:  0xEF53
    Filesystem revision #:    1 (dynamic)
    Filesystem features:      has_journal ext_attr resize_inode dir_index filetype extent 64bit flex_bg sparse_super huge_file uninit_bg dir_nlink extra_isize
    Filesystem flags:         signed_directory_hash 
    Default mount options:    user_xattr acl
    Filesystem state:         clean
    Errors behavior:          Continue
    Filesystem OS type:       Linux
    Inode count:              6553600
    Block count:              104857600
    Reserved block count:     104857
    Free blocks:              103140734
    Free inodes:              6553589
    First block:              1
    Block size:               1024
    Fragment size:            1024
    Group descriptor size:    64
    Reserved GDT blocks:      256
    Blocks per group:         8192
    Fragments per group:      8192
    Inodes per group:         512
    Inode blocks per group:   128
    Flex block group size:    16
    Filesystem created:       Wed May 27 06:17:57 2020
    Last mount time:          n/a
    Last write time:          Wed May 27 06:17:58 2020
    Mount count:              0
    Maximum mount count:      -1
    Last checked:             Wed May 27 06:17:57 2020
    Check interval:           0 (<none>)
    Lifetime writes:          34 MB
    Reserved blocks uid:      0 (user root)
    Reserved blocks gid:      0 (group root)
    First inode:              11
    Inode size:              256
    Required extra isize:     28
    Desired extra isize:      28
    Journal inode:            8
    Default directory hash:   half_md4
    Directory Hash Seed:      c9f747cb-080f-47b7-9af2-4b82205c6094
    Journal backup:           inode blocks
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb5

    5>.指定卷标

    [root@yinzhengjie.com ~]# lsblk /dev/sdb
    NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
    sdb      8:16   0  600G  0 disk 
    ├─sdb1   8:17   0  100G  0 part 
    ├─sdb2   8:18   0  200G  0 part 
    ├─sdb3   8:19   0    1K  0 part 
    ├─sdb5   8:21   0  100G  0 part 
    └─sdb6   8:22   0   80G  0 part 
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# lsblk /dev/sdb
    [root@yinzhengjie.com ~]# mkfs.ext4 -b 1024 -m 0.1 -L "/mnt/sdb6" /dev/sdb6
    mke2fs 1.42.9 (28-Dec-2013)
    Filesystem label=/mnt/sdb6
    OS type: Linux
    Block size=1024 (log=0)
    Fragment size=1024 (log=0)
    Stride=0 blocks, Stripe width=0 blocks
    5242880 inodes, 83886080 blocks
    83886 blocks (0.10%) reserved for the super user
    First data block=1
    Maximum filesystem blocks=117440512
    10240 block groups
    8192 blocks per group, 8192 fragments per group
    512 inodes per group
    Superblock backups stored on blocks: 
        8193, 24577, 40961, 57345, 73729, 204801, 221185, 401409, 663553, 
        1024001, 1990657, 2809857, 5120001, 5971969, 17915905, 19668993, 
        25600001, 53747713
    
    Allocating group tables: done                            
    Writing inode tables: done                            
    Creating journal (32768 blocks): done
    Writing superblocks and filesystem accounting information: done       
    
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# mkfs.ext4 -b 1024 -m 0.1 -L "/mnt/sdb6" /dev/sdb6
    [root@yinzhengjie.com ~]# blkid /dev/sdb6
    /dev/sdb6: LABEL="/mnt/sdb6" UUID="27589e56-158f-4898-91f9-3d052b5978d7" TYPE="ext4" 
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# blkid /dev/sdb6
    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb6
    tune2fs 1.42.9 (28-Dec-2013)
    Filesystem volume name:   /mnt/sdb6
    Last mounted on:          <not available>
    Filesystem UUID:          27589e56-158f-4898-91f9-3d052b5978d7
    Filesystem magic number:  0xEF53
    Filesystem revision #:    1 (dynamic)
    Filesystem features:      has_journal ext_attr resize_inode dir_index filetype extent 64bit flex_bg sparse_super huge_file uninit_bg dir_nlink extra_isize
    Filesystem flags:         signed_directory_hash 
    Default mount options:    user_xattr acl
    Filesystem state:         clean
    Errors behavior:          Continue
    Filesystem OS type:       Linux
    Inode count:              5242880
    Block count:              83886080
    Reserved block count:     83886
    Free blocks:              82505054
    Free inodes:              5242869
    First block:              1
    Block size:               1024
    Fragment size:            1024
    Group descriptor size:    64
    Reserved GDT blocks:      256
    Blocks per group:         8192
    Fragments per group:      8192
    Inodes per group:         512
    Inode blocks per group:   128
    Flex block group size:    16
    Filesystem created:       Wed May 27 12:52:41 2020
    Last mount time:          n/a
    Last write time:          Wed May 27 12:52:42 2020
    Mount count:              0
    Maximum mount count:      -1
    Last checked:             Wed May 27 12:52:41 2020
    Check interval:           0 (<none>)
    Lifetime writes:          34 MB
    Reserved blocks uid:      0 (user root)
    Reserved blocks gid:      0 (group root)
    First inode:              11
    Inode size:              256
    Required extra isize:     28
    Desired extra isize:      28
    Journal inode:            8
    Default directory hash:   half_md4
    Directory Hash Seed:      d8d16075-4b5b-416a-bd87-919bbf8505a4
    Journal backup:           inode blocks
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb6
      温馨提示:
        我们可以使用设备名(比如/dev/sdb6),卷标名(比如“/mnt/sdb6”),UUID来表示一个分区,但我们推荐使用后者,因为UUID可以唯一标识一个设备,而设备名和卷标名并不能唯一标识。比如删除第一个分区时,后面的所有分区编号均会发生变化。

    6>.为数据空间中每多少字节创建一个inode(不应该小于块大小)

    [root@yinzhengjie.com ~]# mkfs.ext4 -i 1024 -b 4096 /dev/sdb6
    mke2fs 1.42.9 (28-Dec-2013)
    Filesystem label=
    OS type: Linux
    Block size=4096 (log=2)
    Fragment size=4096 (log=2)
    Stride=0 blocks, Stripe width=0 blocks
    83886080 inodes, 20971520 blocks
    1048576 blocks (5.00%) reserved for the super user
    First data block=0
    Maximum filesystem blocks=557842432
    2560 block groups
    8192 blocks per group, 8192 fragments per group
    32768 inodes per group
    Superblock backups stored on blocks: 
        8192, 24576, 40960, 57344, 73728, 204800, 221184, 401408, 663552, 
        1024000, 1990656, 2809856, 5120000, 5971968, 17915904, 19668992
    
    Allocating group tables: done                            
    Writing inode tables: done                            
    Creating journal (32768 blocks): done
    Writing superblocks and filesystem accounting information: done     
    
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# mkfs.ext4 -i 1024 -b 4096 /dev/sdb6        #我们将inode的大小设置小于块大小是毫无意义的,因为这意味着很多空间将无法使用,因为一个inode最少要占用一个block。
    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb6
    tune2fs 1.42.9 (28-Dec-2013)
    Filesystem volume name:   <none>
    Last mounted on:          <not available>
    Filesystem UUID:          b07c5586-5b05-4334-91d2-599098f3e222
    Filesystem magic number:  0xEF53
    Filesystem revision #:    1 (dynamic)
    Filesystem features:      has_journal ext_attr resize_inode dir_index filetype extent 64bit flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize
    Filesystem flags:         signed_directory_hash 
    Default mount options:    user_xattr acl
    Filesystem state:         clean
    Errors behavior:          Continue
    Filesystem OS type:       Linux
    Inode count:              83886080
    Block count:              20971520
    Reserved block count:     1048576
    Free blocks:              15672641
    Free inodes:              83886069
    First block:              0
    Block size:               4096
    Fragment size:            4096
    Group descriptor size:    64
    Reserved GDT blocks:      1024
    Blocks per group:         8192
    Fragments per group:      8192
    Inodes per group:         32768
    Inode blocks per group:   2048
    Flex block group size:    16
    Filesystem created:       Wed May 27 13:02:27 2020
    Last mount time:          n/a
    Last write time:          Wed May 27 13:02:29 2020
    Mount count:              0
    Maximum mount count:      -1
    Last checked:             Wed May 27 13:02:27 2020
    Check interval:           0 (<none>)
    Lifetime writes:          135 MB
    Reserved blocks uid:      0 (user root)
    Reserved blocks gid:      0 (group root)
    First inode:              11
    Inode size:              256
    Required extra isize:     28
    Desired extra isize:      28
    Journal inode:            8
    Default directory hash:   half_md4
    Directory Hash Seed:      62d5b9a5-db23-4cec-9c14-dbd1b7499870
    Journal backup:           inode blocks
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb6                 #我们会发现节点数量(Inode count)要远远大于块数量(Block count)
      温馨提示:
        上面我有意将inode大小设置的比block大小要小,其实这样做是毫无意义的,我们通过tune2fs命令也可以看出最终的结果是indoe数量要比block数量要大。
        我们知道一个块大小是存储的基本单元,而一个inode就得占用一个块来存储,而在block数量小于inode数量的情况下,我们会发现在存储数据时,inode还没有使用完,block会先被使用完啦。

    7>.指定分区中创建多少个inode

    [root@yinzhengjie.com ~]# mkfs.ext4 -N 65536 -b 4096 /dev/sdb6
    mke2fs 1.42.9 (28-Dec-2013)
    Filesystem label=
    OS type: Linux
    Block size=4096 (log=2)
    Fragment size=4096 (log=2)
    Stride=0 blocks, Stripe width=0 blocks
    71680 inodes, 20971520 blocks
    1048576 blocks (5.00%) reserved for the super user
    First data block=0
    Maximum filesystem blocks=2168455168
    640 block groups
    32768 blocks per group, 32768 fragments per group
    112 inodes per group
    Superblock backups stored on blocks: 
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 
        4096000, 7962624, 11239424, 20480000
    
    Allocating group tables: done                            
    Writing inode tables: done                            
    Creating journal (32768 blocks): done
    Writing superblocks and filesystem accounting information: done   
    
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# mkfs.ext4 -N 65536 -b 4096 /dev/sdb6
    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb6
    tune2fs 1.42.9 (28-Dec-2013)
    Filesystem volume name:   <none>
    Last mounted on:          <not available>
    Filesystem UUID:          ffaaa3c4-cb73-4d7c-af57-6b2cc24a1929
    Filesystem magic number:  0xEF53
    Filesystem revision #:    1 (dynamic)
    Filesystem features:      has_journal ext_attr resize_inode dir_index filetype extent 64bit flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize
    Filesystem flags:         signed_directory_hash 
    Default mount options:    user_xattr acl
    Filesystem state:         clean
    Errors behavior:          Continue
    Filesystem OS type:       Linux
    Inode count:              71680
    Block count:              20971520
    Reserved block count:     1048576
    Free blocks:              20918496
    Free inodes:              71669
    First block:              0
    Block size:               4096
    Fragment size:            4096
    Group descriptor size:    64
    Reserved GDT blocks:      1024
    Blocks per group:         32768
    Fragments per group:      32768
    Inodes per group:         112
    Inode blocks per group:   7
    Flex block group size:    16
    Filesystem created:       Wed May 27 13:13:31 2020
    Last mount time:          n/a
    Last write time:          Wed May 27 13:13:32 2020
    Mount count:              0
    Maximum mount count:      -1
    Last checked:             Wed May 27 13:13:31 2020
    Check interval:           0 (<none>)
    Lifetime writes:          132 MB
    Reserved blocks uid:      0 (user root)
    Reserved blocks gid:      0 (group root)
    First inode:              11
    Inode size:              256
    Required extra isize:     28
    Desired extra isize:      28
    Journal inode:            8
    Default directory hash:   half_md4
    Directory Hash Seed:      f424d3ee-64c5-4bdc-96dd-2525621d38e3
    Journal backup:           inode blocks
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb6

    三.重新设定EXT系列文件系统可调整参数的值-tune2f2

    1>.tune2fs概述

      tune2fs是用于重新设定ext系列文件系统可调整参数的值,其常用参数如下:
        -l:
          查看指定文件系统超级块信息;super block     
    -L:
          'LABEL‘修改卷标     -m:
          修预留给管理员的空间百分比     
    -j:
          将ext2升级为ext3     
    -O:
          文件系统属性启用或禁用,–O ^has_journal     -o:
          调整文件系统的默认挂载选项,–o ^acl     -U UUID:
          修改UUID号
    [root@yinzhengjie.com ~]# tune2fs 
    tune2fs 1.42.9 (28-Dec-2013)
    Usage: tune2fs [-c max_mounts_count] [-e errors_behavior] [-g group]
        [-i interval[d|m|w]] [-j] [-J journal_options] [-l]
        [-m reserved_blocks_percent] [-o [^]mount_options[,...]] [-p mmp_update_interval]
        [-r reserved_blocks_count] [-u user] [-C mount_count] [-L volume_label]
        [-M last_mounted_dir] [-O [^]feature[,...]]
        [-E extended-option[,...]] [-T last_check_time] [-U UUID]
        [ -I new_inode_size ] device
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# tune2fs                #想要查看更详细的文档可参考"man tune2fs"的帮助信息

    2>.查看指定文件系统超级块信息

    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb1
    tune2fs 1.42.9 (28-Dec-2013)
    Filesystem volume name:   <none>
    Last mounted on:          <not available>
    Filesystem UUID:          d5819b04-a9c3-4a10-a09c-ed1284c36658
    Filesystem magic number:  0xEF53
    Filesystem revision #:    1 (dynamic)
    Filesystem features:      ext_attr resize_inode dir_index filetype sparse_super large_file      #很明显。EXT2文件系统类型是不支持日志功能的,因为它没有"has_journal"功能。
    Filesystem flags:         signed_directory_hash 
    Default mount options:    user_xattr acl   #默认的挂载选项,在CentOS 7默认支持ACL功能,但是在CentOS 6默认为"none"(这意味着如果CentOS 6.x在挂载时没有指定ACL选项就无法使用ACL功能)
    Filesystem state:         clean        #文件系统状态为"clean"表示文件系统是没有问题的,若文件系统出现问题时,该值为"no clean",需要使用相应的工具进行修复。
    Errors behavior:          Continue
    Filesystem OS type:       Linux
    Inode count:              6553600       #Inode的总数量
    Block count:              26214400       #块的数量
    Reserved block count:     1310720       #保留的块数量,默认是"5%",生产环境可以自行调整。
    Free blocks:              25787819      #空闲的blocks数量
    Free inodes:              6553589       #Inode的空闲数量
    First block:              0
    Block size:               4096        #块的大小                                          
    Fragment size:            4096
    Reserved GDT blocks:      1017
    Blocks per group:         32768        #每个组有多少个块
    Fragments per group:      32768
    Inodes per group:         8192
    Inode blocks per group:   512
    Filesystem created:       Wed May 27 05:37:08 2020
    Last mount time:          n/a
    Last write time:          Wed May 27 05:37:50 2020
    Mount count:              0          #挂载次数
    Maximum mount count:      -1          #最大挂载次数
    Last checked:             Wed May 27 05:37:08 2020
    Check interval:           0 (<none>)      #检查间隔
    Reserved blocks uid:      0 (user root)
    Reserved blocks gid:      0 (group root)
    First inode:              11
    Inode size:              256           #一个Inode记录占用磁盘空间大小默认是256个字节。我们可以自定义该inode占用空间大小,取值范围[128,4096],通常情况下保持默认即可。
    Required extra isize:     28
    Desired extra isize:      28
    Default directory hash:   half_md4
    Directory Hash Seed:      4256aab3-4776-4711-8aee-1bcb4f54cc39
    [root@yinzhengjie.com ~]# 

    3>.文件系统启用功能(为ext2文件系统指定日志功能会变成ext3文件系统)

    [root@yinzhengjie.com ~]# blkid /dev/sdb1 
    /dev/sdb1: UUID="d5819b04-a9c3-4a10-a09c-ed1284c36658" TYPE="ext2" 
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# blkid /dev/sdb1
    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb1
    tune2fs 1.42.9 (28-Dec-2013)
    Filesystem volume name:   <none>
    Last mounted on:          <not available>
    Filesystem UUID:          d5819b04-a9c3-4a10-a09c-ed1284c36658
    Filesystem magic number:  0xEF53
    Filesystem revision #:    1 (dynamic)
    Filesystem features:      ext_attr resize_inode dir_index filetype sparse_super large_file
    Filesystem flags:         signed_directory_hash 
    Default mount options:    user_xattr acl
    Filesystem state:         clean
    Errors behavior:          Continue
    Filesystem OS type:       Linux
    Inode count:              6553600
    Block count:              26214400
    Reserved block count:     1310720
    Free blocks:              25787819
    Free inodes:              6553589
    First block:              0
    Block size:               4096
    Fragment size:            4096
    Reserved GDT blocks:      1017
    Blocks per group:         32768
    Fragments per group:      32768
    Inodes per group:         8192
    Inode blocks per group:   512
    Filesystem created:       Wed May 27 05:37:08 2020
    Last mount time:          n/a
    Last write time:          Wed May 27 05:37:50 2020
    Mount count:              0
    Maximum mount count:      -1
    Last checked:             Wed May 27 05:37:08 2020
    Check interval:           0 (<none>)
    Reserved blocks uid:      0 (user root)
    Reserved blocks gid:      0 (group root)
    First inode:              11
    Inode size:              256
    Required extra isize:     28
    Desired extra isize:      28
    Default directory hash:   half_md4
    Directory Hash Seed:      4256aab3-4776-4711-8aee-1bcb4f54cc39
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb1
    [root@yinzhengjie.com ~]# tune2fs -O has_journal /dev/sdb1
    tune2fs 1.42.9 (28-Dec-2013)
    Creating journal inode: done
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# tune2fs -O has_journal /dev/sdb1
    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb1
    tune2fs 1.42.9 (28-Dec-2013)
    Filesystem volume name:   <none>
    Last mounted on:          <not available>
    Filesystem UUID:          d5819b04-a9c3-4a10-a09c-ed1284c36658
    Filesystem magic number:  0xEF53
    Filesystem revision #:    1 (dynamic)
    Filesystem features:      has_journal ext_attr resize_inode dir_index filetype sparse_super large_file
    Filesystem flags:         signed_directory_hash 
    Default mount options:    user_xattr acl
    Filesystem state:         clean
    Errors behavior:          Continue
    Filesystem OS type:       Linux
    Inode count:              6553600
    Block count:              26214400
    Reserved block count:     1310720
    Free blocks:              25755018
    Free inodes:              6553589
    First block:              0
    Block size:               4096
    Fragment size:            4096
    Reserved GDT blocks:      1017
    Blocks per group:         32768
    Fragments per group:      32768
    Inodes per group:         8192
    Inode blocks per group:   512
    Filesystem created:       Wed May 27 05:37:08 2020
    Last mount time:          n/a
    Last write time:          Wed May 27 13:17:30 2020
    Mount count:              0
    Maximum mount count:      -1
    Last checked:             Wed May 27 05:37:08 2020
    Check interval:           0 (<none>)
    Reserved blocks uid:      0 (user root)
    Reserved blocks gid:      0 (group root)
    First inode:              11
    Inode size:              256
    Required extra isize:     28
    Desired extra isize:      28
    Journal inode:            8
    Default directory hash:   half_md4
    Directory Hash Seed:      4256aab3-4776-4711-8aee-1bcb4f54cc39
    Journal backup:           inode blocks
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb1
    [root@yinzhengjie.com ~]# blkid /dev/sdb1 
    /dev/sdb1: UUID="d5819b04-a9c3-4a10-a09c-ed1284c36658" SEC_TYPE="ext2" TYPE="ext3" 
    [root@yinzhengjie.com ~]#
    [root@yinzhengjie.com ~]# blkid /dev/sdb1

    4>.文件系统禁用has_journal功能(为ext3文件系统去掉日志功能会编程ext2文件系统)

    [root@yinzhengjie.com ~]# blkid /dev/sdb1 
    /dev/sdb1: UUID="d5819b04-a9c3-4a10-a09c-ed1284c36658" SEC_TYPE="ext2" TYPE="ext3" 
    [root@yinzhengjie.com ~]#
    [root@yinzhengjie.com ~]# blkid /dev/sdb1
    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb1
    tune2fs 1.42.9 (28-Dec-2013)
    Filesystem volume name:   <none>
    Last mounted on:          <not available>
    Filesystem UUID:          d5819b04-a9c3-4a10-a09c-ed1284c36658
    Filesystem magic number:  0xEF53
    Filesystem revision #:    1 (dynamic)
    Filesystem features:      has_journal ext_attr resize_inode dir_index filetype sparse_super large_file
    Filesystem flags:         signed_directory_hash 
    Default mount options:    user_xattr acl
    Filesystem state:         clean
    Errors behavior:          Continue
    Filesystem OS type:       Linux
    Inode count:              6553600
    Block count:              26214400
    Reserved block count:     1310720
    Free blocks:              25755018
    Free inodes:              6553589
    First block:              0
    Block size:               4096
    Fragment size:            4096
    Reserved GDT blocks:      1017
    Blocks per group:         32768
    Fragments per group:      32768
    Inodes per group:         8192
    Inode blocks per group:   512
    Filesystem created:       Wed May 27 05:37:08 2020
    Last mount time:          n/a
    Last write time:          Wed May 27 13:17:30 2020
    Mount count:              0
    Maximum mount count:      -1
    Last checked:             Wed May 27 05:37:08 2020
    Check interval:           0 (<none>)
    Reserved blocks uid:      0 (user root)
    Reserved blocks gid:      0 (group root)
    First inode:              11
    Inode size:              256
    Required extra isize:     28
    Desired extra isize:      28
    Journal inode:            8
    Default directory hash:   half_md4
    Directory Hash Seed:      4256aab3-4776-4711-8aee-1bcb4f54cc39
    Journal backup:           inode blocks
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb1
    [root@yinzhengjie.com ~]# tune2fs -O ^has_journal /dev/sdb1
    tune2fs 1.42.9 (28-Dec-2013)
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# tune2fs -O ^has_journal /dev/sdb1
    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb1
    tune2fs 1.42.9 (28-Dec-2013)
    Filesystem volume name:   <none>
    Last mounted on:          <not available>
    Filesystem UUID:          d5819b04-a9c3-4a10-a09c-ed1284c36658
    Filesystem magic number:  0xEF53
    Filesystem revision #:    1 (dynamic)
    Filesystem features:      ext_attr resize_inode dir_index filetype sparse_super large_file
    Filesystem flags:         signed_directory_hash 
    Default mount options:    user_xattr acl
    Filesystem state:         clean
    Errors behavior:          Continue
    Filesystem OS type:       Linux
    Inode count:              6553600
    Block count:              26214400
    Reserved block count:     1310720
    Free blocks:              25787819
    Free inodes:              6553589
    First block:              0
    Block size:               4096
    Fragment size:            4096
    Reserved GDT blocks:      1017
    Blocks per group:         32768
    Fragments per group:      32768
    Inodes per group:         8192
    Inode blocks per group:   512
    Filesystem created:       Wed May 27 05:37:08 2020
    Last mount time:          n/a
    Last write time:          Wed May 27 13:24:20 2020
    Mount count:              0
    Maximum mount count:      -1
    Last checked:             Wed May 27 05:37:08 2020
    Check interval:           0 (<none>)
    Reserved blocks uid:      0 (user root)
    Reserved blocks gid:      0 (group root)
    First inode:              11
    Inode size:              256
    Required extra isize:     28
    Desired extra isize:      28
    Default directory hash:   half_md4
    Directory Hash Seed:      4256aab3-4776-4711-8aee-1bcb4f54cc39
    Journal backup:           inode blocks
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb1
    [root@yinzhengjie.com ~]# blkid /dev/sdb1
    /dev/sdb1: UUID="d5819b04-a9c3-4a10-a09c-ed1284c36658" TYPE="ext2" 
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# blkid /dev/sdb1

    四.EXT系统文件系列块分组管理-dumpe2fs

    1>.默认显示分组信息

    [root@yinzhengjie.com ~]# dumpe2fs /dev/sdb5
    dumpe2fs 1.42.9 (28-Dec-2013)
    
    
    
    Filesystem volume name:   <none>
    Last mounted on:          <not available>
    Filesystem UUID:          0e1581cf-51a9-4f5a-b1ad-635ac3364578
    Filesystem magic number:  0xEF53
    Filesystem revision #:    1 (dynamic)
    Filesystem features:      has_journal ext_attr resize_inode dir_index filetype extent 64bit flex_bg sparse_super huge_file uninit_bg dir_nlink extra_isize
    Filesystem flags:         signed_directory_hash 
    Default mount options:    user_xattr acl
    Filesystem state:         clean
    Errors behavior:          Continue
    Filesystem OS type:       Linux
    Inode count:              6553600
    Block count:              104857600
    Reserved block count:     104857
    Free blocks:              103140734
    Free inodes:              6553589
    First block:              1
    Block size:               1024
    Fragment size:            1024
    Group descriptor size:    64
    Reserved GDT blocks:      256
    Blocks per group:         8192
    Fragments per group:      8192
    Inodes per group:         512
    Inode blocks per group:   128
    Flex block group size:    16
    Filesystem created:       Wed May 27 06:17:57 2020
    Last mount time:          n/a
    Last write time:          Wed May 27 06:17:58 2020
    Mount count:              0
    Maximum mount count:      -1
    Last checked:             Wed May 27 06:17:57 2020
    Check interval:           0 (<none>)
    Lifetime writes:          34 MB
    Reserved blocks uid:      0 (user root)
    Reserved blocks gid:      0 (group root)
    First inode:              11
    Inode size:               256
    Required extra isize:     28
    Desired extra isize:      28
    Journal inode:            8
    Default directory hash:   half_md4
    Directory Hash Seed:      c9f747cb-080f-47b7-9af2-4b82205c6094
    Journal backup:           inode blocks
    Journal features:         (none)
    Journal size:             32M
    Journal length:           32768
    Journal sequence:         0x00000001
    Journal start:            0
    
    
    Group 0: (Blocks 1-8192)
      Checksum 0x2b44, unused inodes 501
      Primary superblock at 1, Group descriptors at 2-801
      Reserved GDT blocks at 802-1057
      Block bitmap at 1058 (+1057), Inode bitmap at 1074 (+1073)
      Inode table at 1090-1217 (+1089)
      5041 free blocks, 501 free inodes, 2 directories, 501 unused inodes
      Free blocks: 3152-8192
      Free inodes: 12-512
    Group 1: (Blocks 8193-16384) [INODE_UNINIT]
      Checksum 0x2b24, unused inodes 512
      Backup superblock at 8193, Group descriptors at 8194-8993
      Reserved GDT blocks at 8994-9249
      Block bitmap at 1059 (bg #0 + 1058), Inode bitmap at 1075 (bg #0 + 1074)
      Inode table at 1218-1345 (bg #0 + 1217)
      7135 free blocks, 512 free inodes, 0 directories, 512 unused inodes
      Free blocks: 9250-16384
      Free inodes: 513-1024
    Group 2: (Blocks 16385-24576) [INODE_UNINIT, BLOCK_UNINIT]
      Checksum 0x708b, unused inodes 512
      Block bitmap at 1060 (bg #0 + 1059), Inode bitmap at 1076 (bg #0 + 1075)
      Inode table at 1346-1473 (bg #0 + 1345)
      8192 free blocks, 512 free inodes, 0 directories, 512 unused inodes
      Free blocks: 16385-24576
      Free inodes: 1025-1536
    Group 3: (Blocks 24577-32768) [INODE_UNINIT]
      Checksum 0xc014, unused inodes 512
      Backup superblock at 24577, Group descriptors at 24578-25377
      Reserved GDT blocks at 25378-25633
      Block bitmap at 1061 (bg #0 + 1060), Inode bitmap at 1077 (bg #0 + 1076)
      Inode table at 1474-1601 (bg #0 + 1473)
      7135 free blocks, 512 free inodes, 0 directories, 512 unused inodes
      Free blocks: 25634-32768
      Free inodes: 1537-2048
    Group 4: (Blocks 32769-40960) [INODE_UNINIT, BLOCK_UNINIT]
      Checksum 0xc5c7, unused inodes 512
      Block bitmap at 1062 (bg #0 + 1061), Inode bitmap at 1078 (bg #0 + 1077)
      Inode table at 1602-1729 (bg #0 + 1601)
      8192 free blocks, 512 free inodes, 0 directories, 512 unused inodes
      Free blocks: 32769-40960
      Free inodes: 2049-2560
    Group 5: (Blocks 40961-49152) [INODE_UNINIT]
      Checksum 0x7558, unused inodes 512
      Backup superblock at 40961, Group descriptors at 40962-41761
      Reserved GDT blocks at 41762-42017
      Block bitmap at 1063 (bg #0 + 1062), Inode bitmap at 1079 (bg #0 + 1078)
      Inode table at 1730-1857 (bg #0 + 1729)
      7135 free blocks, 512 free inodes, 0 directories, 512 unused inodes
      Free blocks: 42018-49152
      Free inodes: 2561-3072
    Group 6: (Blocks 49153-57344) [INODE_UNINIT, BLOCK_UNINIT]
      Checksum 0xe6e8, unused inodes 512
      Block bitmap at 1064 (bg #0 + 1063), Inode bitmap at 1080 (bg #0 + 1079)
      Inode table at 1858-1985 (bg #0 + 1857)
      8192 free blocks, 512 free inodes, 0 directories, 512 unused inodes
      Free blocks: 49153-57344
      Free inodes: 3073-3584
    Group 7: (Blocks 57345-65536) [INODE_UNINIT]
      Checksum 0x5677, unused inodes 512
      Backup superblock at 57345, Group descriptors at 57346-58145
      Reserved GDT blocks at 58146-58401
      Block bitmap at 1065 (bg #0 + 1064), Inode bitmap at 1081 (bg #0 + 1080)
      Inode table at 1986-2113 (bg #0 + 1985)
      7135 free blocks, 512 free inodes, 0 directories, 512 unused inodes
      Free blocks: 58402-65536
      Free inodes: 3585-4096
    Group 8: (Blocks 65537-73728) [INODE_UNINIT, BLOCK_UNINIT]
      Checksum 0x0b8f, unused inodes 512
      Block bitmap at 1066 (bg #0 + 1065), Inode bitmap at 1082 (bg #0 + 1081)
      Inode table at 2114-2241 (bg #0 + 2113)
      8192 free blocks, 512 free inodes, 0 directories, 512 unused inodes
      Free blocks: 65537-73728
      Free inodes: 4097-4608
    Group 9: (Blocks 73729-81920) [INODE_UNINIT]
      Checksum 0xbb10, unused inodes 512
      Backup superblock at 73729, Group descriptors at 73730-74529
      Reserved GDT blocks at 74530-74785
      Block bitmap at 1067 (bg #0 + 1066), Inode bitmap at 1083 (bg #0 + 1082)
      Inode table at 2242-2369 (bg #0 + 2241)
      7135 free blocks, 512 free inodes, 0 directories, 512 unused inodes
      Free blocks: 74786-81920
      Free inodes: 4609-5120
    Group 10: (Blocks 81921-90112) [INODE_UNINIT, BLOCK_UNINIT]
      Checksum 0xe0bf, unused inodes 512
      Block bitmap at 1068 (bg #0 + 1067), Inode bitmap at 1084 (bg #0 + 1083)
    
    ......
    
    Group 12796: (Blocks 104824833-104833024) [INODE_UNINIT, BLOCK_UNINIT]
      Checksum 0x82eb, unused inodes 512
      Block bitmap at 104726541 (bg #12784 + 12), Inode bitmap at 104726557 (bg #12784 + 28)
      Inode table at 104728097-104728224 (bg #12784 + 1568)
      8192 free blocks, 512 free inodes, 0 directories, 512 unused inodes
      Free blocks: 104824833-104833024
      Free inodes: 6551553-6552064
    Group 12797: (Blocks 104833025-104841216) [INODE_UNINIT, BLOCK_UNINIT]
      Checksum 0xf773, unused inodes 512
      Block bitmap at 104726542 (bg #12784 + 13), Inode bitmap at 104726558 (bg #12784 + 29)
      Inode table at 104728225-104728352 (bg #12784 + 1696)
      8192 free blocks, 512 free inodes, 0 directories, 512 unused inodes
      Free blocks: 104833025-104841216
      Free inodes: 6552065-6552576
    Group 12798: (Blocks 104841217-104849408) [INODE_UNINIT, BLOCK_UNINIT]
      Checksum 0xadd5, unused inodes 512
      Block bitmap at 104726543 (bg #12784 + 14), Inode bitmap at 104726559 (bg #12784 + 30)
      Inode table at 104728353-104728480 (bg #12784 + 1824)
      8192 free blocks, 512 free inodes, 0 directories, 512 unused inodes
      Free blocks: 104841217-104849408
      Free inodes: 6552577-6553088
    Group 12799: (Blocks 104849409-104857599) [INODE_UNINIT]
      Checksum 0xea16, unused inodes 512
      Block bitmap at 104726544 (bg #12784 + 15), Inode bitmap at 104726560 (bg #12784 + 31)
      Inode table at 104728481-104728608 (bg #12784 + 1952)
      8191 free blocks, 512 free inodes, 0 directories, 512 unused inodes
      Free blocks: 104849409-104857599
      Free inodes: 6553089-6553600
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# dumpe2fs /dev/sdb5

    2>.查看超级块信息,不显示分组信息(等效于"tune2fs -l"选项)

    [root@yinzhengjie.com ~]# dumpe2fs -h /dev/sdb5
    dumpe2fs 1.42.9 (28-Dec-2013)
    Filesystem volume name:   <none>
    Last mounted on:          <not available>
    Filesystem UUID:          0e1581cf-51a9-4f5a-b1ad-635ac3364578
    Filesystem magic number:  0xEF53
    Filesystem revision #:    1 (dynamic)
    Filesystem features:      has_journal ext_attr resize_inode dir_index filetype extent 64bit flex_bg sparse_super huge_file uninit_bg dir_nlink extra_isize
    Filesystem flags:         signed_directory_hash 
    Default mount options:    user_xattr acl
    Filesystem state:         clean
    Errors behavior:          Continue
    Filesystem OS type:       Linux
    Inode count:              6553600
    Block count:              104857600
    Reserved block count:     104857
    Free blocks:              103140734
    Free inodes:              6553589
    First block:              1
    Block size:               1024
    Fragment size:            1024
    Group descriptor size:    64
    Reserved GDT blocks:      256
    Blocks per group:         8192
    Fragments per group:      8192
    Inodes per group:         512
    Inode blocks per group:   128
    Flex block group size:    16
    Filesystem created:       Wed May 27 06:17:57 2020
    Last mount time:          n/a
    Last write time:          Wed May 27 06:17:58 2020
    Mount count:              0
    Maximum mount count:      -1
    Last checked:             Wed May 27 06:17:57 2020
    Check interval:           0 (<none>)
    Lifetime writes:          34 MB
    Reserved blocks uid:      0 (user root)
    Reserved blocks gid:      0 (group root)
    First inode:              11
    Inode size:              256
    Required extra isize:     28
    Desired extra isize:      28
    Journal inode:            8
    Default directory hash:   half_md4
    Directory Hash Seed:      c9f747cb-080f-47b7-9af2-4b82205c6094
    Journal backup:           inode blocks
    Journal features:         (none)
    Journal size:             32M
    Journal length:           32768
    Journal sequence:         0x00000001
    Journal start:            0
    
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# dumpe2fs -h /dev/sdb5

    五.创建CentOS 7默认的XFS文件系统

    [root@yinzhengjie.com ~]# mkfs.xfs -f /dev/sdb1           #如果"/dev/sdb1"这个分区已经有文件系统了,此时我们想要创建XFS文件系统需要加"-f"参数强制创建XFS文件系统。
    meta-data=/dev/sdb1              isize=512    agcount=4, agsize=6553600 blks
             =                       sectsz=512   attr=2, projid32bit=1
             =                       crc=1        finobt=0, sparse=0
    data     =                       bsize=4096   blocks=26214400, imaxpct=25
             =                       sunit=0      swidth=0 blks
    naming   =version 2              bsize=4096   ascii-ci=0 ftype=1
    log      =internal log           bsize=4096   blocks=12800, version=2
             =                       sectsz=512   sunit=0 blks, lazy-count=1
    realtime =none                   extsz=4096   blocks=0, rtextents=0
    [root@yinzhengjie.com ~]# 

     

    六.管理ext系列文件系统的LABEL工具-e2lable

    [root@yinzhengjie.com ~]# blkid /dev/sdb2
    /dev/sdb2: UUID="15028503-abd5-4bc7-9e35-2e745662d42d" TYPE="ext4" 
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# e2label /dev/sdb2 /mnt/sdb2                  #为EXT系列的文件系统加卷标
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# blkid /dev/sdb2
    /dev/sdb2: LABEL="/mnt/sdb2" UUID="15028503-abd5-4bc7-9e35-2e745662d42d" TYPE="ext4" 
    [root@yinzhengjie.com ~]# 

    七.块设备属性信息查看-blkid

    1>.blkid帮助信息

    [root@yinzhengjie.com ~]# blkid  -help
    blkid from util-linux 2.23.2  (libblkid 2.23.0, 25-Apr-2013)
    Usage:
     blkid -L <label> | -U <uuid>
    
     blkid [-c <file>] [-ghlLv] [-o <format>] [-s <tag>] 
           [-t <token>] [<dev> ...]
    
     blkid -p [-s <tag>] [-O <offset>] [-S <size>] 
           [-o <format>] <dev> ...
    
     blkid -i [-s <tag>] [-o <format>] <dev> ...
    
    Options:
     -c <file>   read from <file> instead of reading from the default
                   cache file (-c /dev/null means no cache)
     -d          don't encode non-printing characters
     -h          print this usage message and exit
     -g          garbage collect the blkid cache
     -o <format> output format; can be one of:
                   value, device, export or full; (default: full)
     -k          list all known filesystems/RAIDs and exit
     -s <tag>    show specified tag(s) (default show all tags)
     -t <token>  find device with a specific token (NAME=value pair)
     -l          look up only first device with token specified by -t
     -L <label>  convert LABEL to device name
     -U <uuid>   convert UUID to device name
     -V          print version and exit
     <dev>       specify device(s) to probe (default: all devices)
    
    Low-level probing options:
     -p          low-level superblocks probing (bypass cache)
     -i          gather information about I/O limits
     -S <size>   overwrite device size
     -O <offset> probe at the given offset
     -u <list>   filter by "usage" (e.g. -u filesystem,raid)
     -n <list>   filter by filesystem type (e.g. -n vfat,ext3)
    
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# blkid -help            #想要查看更详细的帮助文档可参考"man blkid"

    2>.blkid默认查看所有的设备属性信息

    [root@yinzhengjie.com ~]# blkid 
    /dev/sdb1: UUID="da883b9f-c5e6-4dee-8376-dfbae3eac795" TYPE="xfs" 
    /dev/sdb2: LABEL="/mnt/sdb2" UUID="15028503-abd5-4bc7-9e35-2e745662d42d" TYPE="ext4" 
    /dev/sdb5: UUID="0e1581cf-51a9-4f5a-b1ad-635ac3364578" TYPE="ext4" 
    /dev/sda2: UUID="1865a93f-6113-4097-89dc-8c4ea5fdf68c" TYPE="xfs" PARTUUID="e85154fa-bbc8-43c1-90f0-676000195a97" 
    /dev/sda3: UUID="lNmzXe-Whhd-NTtI-C55A-7m4x-CudG-1Q556q" TYPE="LVM2_member" PARTUUID="fa2e251a-d220-415f-acc7-da94b7a2d1b4" 
    /dev/sdb6: UUID="ffaaa3c4-cb73-4d7c-af57-6b2cc24a1929" TYPE="ext4" 
    /dev/mapper/centos-root: UUID="c0160ecb-06e4-497e-813c-53690b4a6109" TYPE="xfs" 
    /dev/mapper/centos-yinzhengjie: UUID="6a2643fb-8d55-44cd-b41e-b5f2709ef855" TYPE="xfs" 
    /dev/sda1: PARTUUID="8f500d9c-87b9-421d-8ce0-8c385b73bf08" 
    /dev/sda4: PARTUUID="814caa31-3a7e-499d-8b7d-cc3017473ba8" 
    /dev/sdc1: PARTLABEL="Linux filesystem" PARTUUID="c79743bd-f7de-43da-8c4f-5f4380b215a4" 
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# blkid

    3>.根据指定的LABEL来查找对应的设备

    [root@yinzhengjie.com ~]# blkid 
    /dev/sdb1: UUID="da883b9f-c5e6-4dee-8376-dfbae3eac795" TYPE="xfs" 
    /dev/sdb2: LABEL="/mnt/sdb2" UUID="15028503-abd5-4bc7-9e35-2e745662d42d" TYPE="ext4" 
    /dev/sdb5: UUID="0e1581cf-51a9-4f5a-b1ad-635ac3364578" TYPE="ext4" 
    /dev/sda2: UUID="1865a93f-6113-4097-89dc-8c4ea5fdf68c" TYPE="xfs" PARTUUID="e85154fa-bbc8-43c1-90f0-676000195a97" 
    /dev/sda3: UUID="lNmzXe-Whhd-NTtI-C55A-7m4x-CudG-1Q556q" TYPE="LVM2_member" PARTUUID="fa2e251a-d220-415f-acc7-da94b7a2d1b4" 
    /dev/sdb6: UUID="ffaaa3c4-cb73-4d7c-af57-6b2cc24a1929" TYPE="ext4" 
    /dev/mapper/centos-root: UUID="c0160ecb-06e4-497e-813c-53690b4a6109" TYPE="xfs" 
    /dev/mapper/centos-yinzhengjie: UUID="6a2643fb-8d55-44cd-b41e-b5f2709ef855" TYPE="xfs" 
    /dev/sda1: PARTUUID="8f500d9c-87b9-421d-8ce0-8c385b73bf08" 
    /dev/sda4: PARTUUID="814caa31-3a7e-499d-8b7d-cc3017473ba8" 
    /dev/sdc1: PARTLABEL="Linux filesystem" PARTUUID="c79743bd-f7de-43da-8c4f-5f4380b215a4" 
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# blkid -L /mnt/sdb2
    /dev/sdb2
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# blkid -L /mnt/sdb2

    4>.根据指定的UUID来查找对应的设备案例(找到"/boot"对应的设备名称)

    [root@yinzhengjie.com ~]# cat /etc/fstab 
    
    #
    # /etc/fstab
    # Created by anaconda on Mon Jan 20 04:18:36 2020
    #
    # Accessible filesystems, by reference, are maintained under '/dev/disk'
    # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
    #
    /dev/mapper/centos-root /                       xfs     defaults        0 0
    UUID=1865a93f-6113-4097-89dc-8c4ea5fdf68c /boot                   xfs     defaults        0 0
    /dev/mapper/centos-yinzhengjie /yinzhengjie            xfs     defaults,noatime,nodiratime       0 0
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# sed -rn 's#^UUID=(.*) /boot .*#1#p' /etc/fstab 
    1865a93f-6113-4097-89dc-8c4ea5fdf68c
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# blkid -U `sed -rn 's#^UUID=(.*) /boot .*#1#p' /etc/fstab`
    /dev/sda2
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# blkid -U `sed -rn 's#^UUID=(.*) /boot .*#1#p' /etc/fstab`                    #解法一
    [root@yinzhengjie.com ~]# cat /etc/fstab 
    
    #
    # /etc/fstab
    # Created by anaconda on Mon Jan 20 04:18:36 2020
    #
    # Accessible filesystems, by reference, are maintained under '/dev/disk'
    # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
    #
    /dev/mapper/centos-root /                       xfs     defaults        0 0
    UUID=1865a93f-6113-4097-89dc-8c4ea5fdf68c /boot                   xfs     defaults        0 0
    /dev/mapper/centos-yinzhengjie /yinzhengjie            xfs     defaults,noatime,nodiratime       0 0
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# grep "/boot" /etc/fstab | awk '{print $1}' | awk -F "=" '{print $2}'
    1865a93f-6113-4097-89dc-8c4ea5fdf68c
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# blkid -U `grep "/boot" /etc/fstab | awk '{print $1}' | awk -F "=" '{print $2}'`
    /dev/sda2
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# blkid -U `grep "/boot" /etc/fstab | awk '{print $1}' | awk -F "=" '{print $2}'`       #解法二

    七.查找分区工具-findfs

    1>.findfs帮助信息

    [root@yinzhengjie.com ~]# findfs -h
    
    Usage:
     findfs [options] {LABEL,UUID,PARTUUID,PARTLABEL}=<value>
    
    Options:
     -h, --help     display this help and exit
     -V, --version  output version information and exit
    
    For more details see findfs(8).
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# findfs -h          #更多信息参考"man findfs"帮助信息

    2>.根据指定的LABEL来查找对应的设备

    [root@yinzhengjie.com ~]# blkid 
    /dev/sdb1: UUID="da883b9f-c5e6-4dee-8376-dfbae3eac795" TYPE="xfs" 
    /dev/sdb2: LABEL="/mnt/sdb2" UUID="15028503-abd5-4bc7-9e35-2e745662d42d" TYPE="ext4" 
    /dev/sdb5: UUID="0e1581cf-51a9-4f5a-b1ad-635ac3364578" TYPE="ext4" 
    /dev/sda2: UUID="1865a93f-6113-4097-89dc-8c4ea5fdf68c" TYPE="xfs" PARTUUID="e85154fa-bbc8-43c1-90f0-676000195a97" 
    /dev/sda3: UUID="lNmzXe-Whhd-NTtI-C55A-7m4x-CudG-1Q556q" TYPE="LVM2_member" PARTUUID="fa2e251a-d220-415f-acc7-da94b7a2d1b4" 
    /dev/sdb6: UUID="ffaaa3c4-cb73-4d7c-af57-6b2cc24a1929" TYPE="ext4" 
    /dev/mapper/centos-root: UUID="c0160ecb-06e4-497e-813c-53690b4a6109" TYPE="xfs" 
    /dev/mapper/centos-yinzhengjie: UUID="6a2643fb-8d55-44cd-b41e-b5f2709ef855" TYPE="xfs" 
    /dev/sda1: PARTUUID="8f500d9c-87b9-421d-8ce0-8c385b73bf08" 
    /dev/sda4: PARTUUID="814caa31-3a7e-499d-8b7d-cc3017473ba8" 
    /dev/sdc1: PARTLABEL="Linux filesystem" PARTUUID="c79743bd-f7de-43da-8c4f-5f4380b215a4" 
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# findfs LABEL=/mnt/sdb2
    /dev/sdb2
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# findfs LABEL=/mnt/sdb2

    3>.根据指定的UUID来查找对应的设备案例(找到"/boot"对应的设备名称)

    [root@yinzhengjie.com ~]# cat /etc/fstab 
    
    #
    # /etc/fstab
    # Created by anaconda on Mon Jan 20 04:18:36 2020
    #
    # Accessible filesystems, by reference, are maintained under '/dev/disk'
    # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
    #
    /dev/mapper/centos-root /                       xfs     defaults        0 0
    UUID=1865a93f-6113-4097-89dc-8c4ea5fdf68c /boot                   xfs     defaults        0 0
    /dev/mapper/centos-yinzhengjie /yinzhengjie            xfs     defaults,noatime,nodiratime       0 0
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# findfs UUID=`sed -rn 's#^UUID=(.*) /boot .*#1#p' /etc/fstab`
    /dev/sda2
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# findfs UUID=`sed -rn 's#^UUID=(.*) /boot .*#1#p' /etc/fstab`
    [root@yinzhengjie.com ~]# cat /etc/fstab 
    
    #
    # /etc/fstab
    # Created by anaconda on Mon Jan 20 04:18:36 2020
    #
    # Accessible filesystems, by reference, are maintained under '/dev/disk'
    # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
    #
    /dev/mapper/centos-root /                       xfs     defaults        0 0
    UUID=1865a93f-6113-4097-89dc-8c4ea5fdf68c /boot                   xfs     defaults        0 0
    /dev/mapper/centos-yinzhengjie /yinzhengjie            xfs     defaults,noatime,nodiratime       0 0
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# findfs UUID=`sed -rn 's#^UUID=(.*) /boot .*#1#p' /etc/fstab`
    /dev/sda2
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# findfs UUID=`grep "/boot" /etc/fstab | awk '{print $1}' | awk -F "=" '{print $2}'`
    /dev/sda2
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# findfs UUID=`grep "/boot" /etc/fstab | awk '{print $1}' | awk -F "=" '{print $2}'`

    八.文件系统检测和修复

      文件系统故障常发生于死机或者非正常关机之后,挂载为文件系统标记为“no clean”
    
      温馨提示:
        一定不要在挂载状态下修复

    1>.挂载文件系统

    [root@yinzhengjie.com ~]# lsblk /dev/sdb
    NAME   MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
    sdb      8:16   0  600G  0 disk 
    ├─sdb1   8:17   0  100G  0 part 
    ├─sdb2   8:18   0  200G  0 part 
    ├─sdb3   8:19   0    1K  0 part 
    ├─sdb5   8:21   0  100G  0 part 
    └─sdb6   8:22   0   80G  0 part 
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# lsblk /dev/sdb
    [root@yinzhengjie.com ~]# blkid /dev/sdb5
    /dev/sdb5: UUID="0e1581cf-51a9-4f5a-b1ad-635ac3364578" TYPE="ext4" 
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# blkid /dev/sdb5
    [root@yinzhengjie.com ~]# df -h
    Filesystem                      Size  Used Avail Use% Mounted on
    /dev/mapper/centos-root         500G  3.5G  497G   1% /
    devtmpfs                        2.0G     0  2.0G   0% /dev
    tmpfs                           2.0G     0  2.0G   0% /dev/shm
    tmpfs                           2.0G   12M  2.0G   1% /run
    tmpfs                           2.0G     0  2.0G   0% /sys/fs/cgroup
    /dev/sda2                      1014M  133M  882M  14% /boot
    /dev/mapper/centos-yinzhengjie  1.6T  416M  1.6T   1% /yinzhengjie
    tmpfs                           394M     0  394M   0% /run/user/0
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# mount /dev/sdb5 /mnt
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# df -h
    Filesystem                      Size  Used Avail Use% Mounted on
    /dev/mapper/centos-root         500G  3.5G  497G   1% /
    devtmpfs                        2.0G     0  2.0G   0% /dev
    tmpfs                           2.0G     0  2.0G   0% /dev/shm
    tmpfs                           2.0G   12M  2.0G   1% /run
    tmpfs                           2.0G     0  2.0G   0% /sys/fs/cgroup
    /dev/sda2                      1014M  133M  882M  14% /boot
    /dev/mapper/centos-yinzhengjie  1.6T  416M  1.6T   1% /yinzhengjie
    tmpfs                           394M     0  394M   0% /run/user/0
    /dev/sdb5                        99G  4.8M   99G   1% /mnt
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# mount /dev/sdb5 /mnt
    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb5
    tune2fs 1.42.9 (28-Dec-2013)
    Filesystem volume name:   <none>
    Last mounted on:          <not available>
    Filesystem UUID:          0e1581cf-51a9-4f5a-b1ad-635ac3364578
    Filesystem magic number:  0xEF53
    Filesystem revision #:    1 (dynamic)
    Filesystem features:      has_journal ext_attr resize_inode dir_index filetype needs_recovery extent 64bit flex_bg sparse_super huge_file uninit_bg dir_nlink extra_isize
    Filesystem flags:         signed_directory_hash 
    Default mount options:    user_xattr acl
    Filesystem state:         clean
    Errors behavior:          Continue
    Filesystem OS type:       Linux
    Inode count:              6553600
    Block count:              104857600
    Reserved block count:     104857
    Free blocks:              103140734
    Free inodes:              6553589
    First block:              1
    Block size:               1024
    Fragment size:            1024
    Group descriptor size:    64
    Reserved GDT blocks:      256
    Blocks per group:         8192
    Fragments per group:      8192
    Inodes per group:         512
    Inode blocks per group:   128
    Flex block group size:    16
    Filesystem created:       Wed May 27 06:17:57 2020
    Last mount time:          Wed May 27 14:21:59 2020
    Last write time:          Wed May 27 14:21:59 2020
    Mount count:              1
    Maximum mount count:      -1
    Last checked:             Wed May 27 06:17:57 2020
    Check interval:           0 (<none>)
    Lifetime writes:          34 MB
    Reserved blocks uid:      0 (user root)
    Reserved blocks gid:      0 (group root)
    First inode:              11
    Inode size:              256
    Required extra isize:     28
    Desired extra isize:      28
    Journal inode:            8
    Default directory hash:   half_md4
    Directory Hash Seed:      c9f747cb-080f-47b7-9af2-4b82205c6094
    Journal backup:           inode blocks
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb5
    [root@yinzhengjie.com ~]# cp -r /etc/ /mnt/
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# ll /mnt/
    total 17
    drwxr-xr-x 77 root root  5120 May 27 14:32 etc
    drwx------  2 root root 12288 May 27 06:17 lost+found
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# ls /mnt/etc/
    adjtime                  csh.cshrc                gnupg        krb5.conf                 my.cnf                printcap             rwtab           sysctl.conf
    aliases                  csh.login                GREP_COLORS  krb5.conf.d               my.cnf.d              profile              rwtab.d         sysctl.conf-2020-01-20
    aliases.db               dbus-1                   groff        ld.so.cache               NetworkManager        profile.d            sasl2           sysctl.d
    alternatives             default                  group        ld.so.conf                networks              protocols            securetty       systemd
    anacrontab               depmod.d                 group-       ld.so.conf.d              nsswitch.conf         python               security        system-release
    asound.conf              dhcp                     grub2.cfg    libaudit.conf             nsswitch.conf.bak     rc0.d                selinux         system-release-cpe
    audisp                   DIR_COLORS               grub.d       libnl                     nsswitch.conf.rpmnew  rc1.d                services        terminfo
    audit                    DIR_COLORS.256color      gshadow      libuser.conf              ntp                   rc2.d                sestatus.conf   tmpfiles.d
    bash_completion.d        DIR_COLORS.lightbgcolor  gshadow-     locale.conf               openldap              rc3.d                shadow          tuned
    bashrc                   docker                   gss          localtime                 opt                   rc4.d                shadow-         udev
    binfmt.d                 dracut.conf              host.conf    login.defs                os-release            rc5.d                shells          vconsole.conf
    centos-release           dracut.conf.d            hostname     logrotate.conf            pam.d                 rc6.d                skel            vimrc
    centos-release-upstream  e2fsck.conf              hosts        logrotate.d               passwd                rc.d                 ssh             virc
    chkconfig.d              environment              hosts.allow  lvm                       passwd-               rc.local             ssl             wgetrc
    containerd               ethertypes               hosts.deny   machine-id                pkcs11                redhat-release       statetab        wpa_supplicant
    cron.d                   exports                  init.d       magic                     pki                   redis.conf           statetab.d      X11
    cron.daily               favicon.png              inittab      makedumpfile.conf.sample  plymouth              redis-sentinel.conf  subgid          xdg
    cron.deny                filesystems              inputrc      man_db.conf               pm                    resolv.conf          subuid          xinetd.d
    cron.hourly              firewalld                iproute2     mke2fs.conf               polkit-1              resolv.conf.save     sudo.conf       yum
    cron.monthly             fstab                    issue        modprobe.d                popt.d                rpc                  sudoers         yum.conf
    crontab                  gcrypt                   issue.net    modules-load.d            postfix               rpm                  sudoers.d       yum.repos.d
    cron.weekly              GeoIP.conf               kdump.conf   motd                      ppp                   rsyslog.conf         sudo-ldap.conf
    crypttab                 GeoIP.conf.default       kernel       mtab                      prelink.conf.d        rsyslog.d            sysconfig
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# cp -r /etc/ /mnt/

    2>.模拟破坏文件系统

    [root@yinzhengjie.com ~]# dd if=/dev/zero of=/dev/sdb5 bs=1M count=3            #破坏文件系统时并不需要把整个硬盘全部清0,我们可以只把前面一部分数据清空即可, 比如我只将该分区的前3M数据清空。
    3+0 records in
    3+0 records out
    3145728 bytes (3.1 MB) copied, 0.292628 s, 10.7 MB/s
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb5                        #很明显,我们发现tune2fs工具已经无法查看超级快(super block)信息啦~
    tune2fs 1.42.9 (28-Dec-2013)
    tune2fs: Bad magic number in super-block while trying to open /dev/sdb5
    Couldn't find valid filesystem superblock.
    [root@yinzhengjie.com ~]# 

    3>.修复文件系统(数据依旧丢失)

    [root@yinzhengjie.com ~]# df -h
    Filesystem                      Size  Used Avail Use% Mounted on
    /dev/mapper/centos-root         500G  3.5G  497G   1% /
    devtmpfs                        2.0G     0  2.0G   0% /dev
    tmpfs                           2.0G     0  2.0G   0% /dev/shm
    tmpfs                           2.0G   12M  2.0G   1% /run
    tmpfs                           2.0G     0  2.0G   0% /sys/fs/cgroup
    /dev/sda2                      1014M  133M  882M  14% /boot
    /dev/mapper/centos-yinzhengjie  1.6T  416M  1.6T   1% /yinzhengjie
    tmpfs                           394M     0  394M   0% /run/user/0
    /dev/sdb5                        16Z   16Z   99G 100% /mnt
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# umount /mnt/
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# df -h
    Filesystem                      Size  Used Avail Use% Mounted on
    /dev/mapper/centos-root         500G  3.5G  497G   1% /
    devtmpfs                        2.0G     0  2.0G   0% /dev
    tmpfs                           2.0G     0  2.0G   0% /dev/shm
    tmpfs                           2.0G   12M  2.0G   1% /run
    tmpfs                           2.0G     0  2.0G   0% /sys/fs/cgroup
    /dev/sda2                      1014M  133M  882M  14% /boot
    /dev/mapper/centos-yinzhengjie  1.6T  416M  1.6T   1% /yinzhengjie
    tmpfs                           394M     0  394M   0% /run/user/0
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# umount /mnt/                            #先卸载
    [root@yinzhengjie.com ~]# fsck -y /dev/sdb5 
    fsck from util-linux 2.23.2
    e2fsck 1.42.9 (28-Dec-2013)
    /dev/sdb5 was not cleanly unmounted, check forced.
    Resize inode not valid.  Recreate? yes
    
    Pass 1: Checking inodes, blocks, and sizes
    Root inode is not a directory.  Clear? yes
    
    Pass 2: Checking directory structure
    Entry '..' in <2>/<2424833> (2424833) has deleted/unused inode 2.  Clear? yes
    
    Pass 3: Checking directory connectivity
    Root inode not allocated.  Allocate? yes
    
    Unconnected directory inode 2424833 (...)
    Connect to /lost+found? yes
    
    /lost+found not found.  Create? yes
    
    Pass 4: Checking reference counts
    Inode 2424833 ref count is 78, should be 77.  Fix? yes
    
    Pass 5: Checking group summary information
    Block bitmap differences:  +(1--3138) +(8193--9249) +(9281--9284) +(9297--9312) +(9329--9344) +(10241--17997) +(18433--22273) +(22529--25633) +(26625--30465) +(32769--34561
    ) +(40961--42017) +(57345--58401) +(73729--74785) -(52305921--52338688)Fix? yes
    
    Free blocks count wrong for group #0 (5039, counted=5052).
    Fix? yes
    
    Free blocks count wrong for group #1 (7135, counted=955).
    Fix? yes
    
    Free blocks count wrong for group #2 (8192, counted=690).
    Fix? yes
    
    Free blocks count wrong for group #3 (7135, counted=3294).
    Fix? yes
    
    Free blocks count wrong for group #4 (8192, counted=6399).
    Fix? yes
    
    Free blocks count wrong for group #4736 (6112, counted=6076).
    Fix? yes
    
    Free blocks count wrong for group #4737 (8192, counted=7136).
    Fix? yes
    
    Free blocks count wrong for group #4752 (6112, counted=6080).
    Fix? yes
    
    Free blocks count wrong for group #4753 (8192, counted=7996).
    Fix? yes
    
    Free blocks count wrong for group #4768 (6112, counted=6080).
    Fix? yes
    
    Free blocks count wrong for group #4769 (8192, counted=7213).
    Fix? yes
    
    Free blocks count wrong for group #4784 (6112, counted=6080).
    Fix? yes
    
    Free blocks count wrong for group #4785 (8192, counted=7955).
    Fix? yes
    
    Free blocks count wrong for group #4800 (6112, counted=6080).
    Fix? yes
    
    Free blocks count wrong for group #4801 (8192, counted=7513).
    Fix? yes
    
    Free blocks count wrong for group #4816 (6112, counted=6071).
    Fix? yes
    
    Free blocks count wrong for group #4817 (8192, counted=5555).
    Fix? yes
    
    Free blocks count wrong for group #4832 (6112, counted=6080).
    Fix? yes
    
    Free blocks count wrong for group #4833 (8192, counted=7621).
    Fix? yes
    
    Free blocks count wrong for group #4848 (6112, counted=6080).
    Fix? yes
    
    Free blocks count wrong for group #4849 (8192, counted=7672).
    Fix? yes
    
    Free blocks count wrong for group #4864 (6112, counted=6080).
    Fix? yes
    
    Free blocks count wrong for group #4865 (8192, counted=7704).
    Fix? yes
    
    Free blocks count wrong for group #4880 (6112, counted=6080).
    Fix? yes
    
    Free blocks count wrong for group #4881 (8192, counted=7683).
    Fix? yes
    
    Free blocks count wrong for group #4896 (6112, counted=6080).
    Fix? yes
    
    Free blocks count wrong for group #4897 (8192, counted=7703).
    Fix? yes
    
    Free blocks count wrong for group #4912 (6112, counted=6080).
    Fix? yes
    
    Free blocks count wrong for group #4913 (8192, counted=7684).
    Fix? yes
    
    Free blocks count wrong for group #4928 (6112, counted=6080).
    Fix? yes
    
    Free blocks count wrong for group #4929 (8192, counted=7735).
    Fix? yes
    
    Free blocks count wrong for group #4944 (6112, counted=6080).
    Fix? yes
    
    Free blocks count wrong for group #4945 (8192, counted=7678).
    Fix? yes
    
    Free blocks count wrong for group #4960 (6112, counted=6080).
    Fix? yes
    
    Free blocks count wrong for group #4961 (8192, counted=7651).
    Fix? yes
    
    Free blocks count wrong for group #4976 (6112, counted=6080).
    Fix? yes
    
    Free blocks count wrong for group #4977 (8192, counted=7630).
    Fix? yes
    
    Free blocks count wrong for group #4992 (6112, counted=6080).
    Fix? yes
    
    Free blocks count wrong for group #4993 (8192, counted=7590).
    Fix? yes
    
    Free blocks count wrong for group #5008 (6112, counted=6080).
    Fix? yes
    
    Free blocks count wrong for group #5009 (8192, counted=7610).
    Fix? yes
    
    Free blocks count wrong for group #5024 (6112, counted=6089).
    Fix? yes
    
    Free blocks count wrong for group #5025 (8192, counted=8001).
    Fix? yes
    
    Free blocks count wrong for group #6385 (0, counted=8192).
    Fix? yes
    
    Free blocks count wrong for group #6386 (0, counted=8192).
    Fix? yes
    
    Free blocks count wrong for group #6387 (0, counted=8192).
    Fix? yes
    
    Free blocks count wrong for group #6388 (0, counted=8192).
    Fix? yes
    
    Free blocks count wrong (103107964, counted=103108499).
    Fix? yes
    
    Inode bitmap differences:  +1 +(3--10)
    Fix? yes
    
    Free inodes count wrong for group #0 (500, counted=501).
    Fix? yes
    
    Directories count wrong for group #0 (3, counted=2).
    Fix? yes
    
    Free inodes count wrong for group #4736 (512, counted=252).
    Fix? yes
    
    Directories count wrong for group #4736 (0, counted=32).
    Fix? yes
    
    Free inodes count wrong for group #4752 (512, counted=420).
    Fix? yes
    
    Directories count wrong for group #4752 (0, counted=32).
    Fix? yes
    
    Free inodes count wrong for group #4768 (512, counted=431).
    Fix? yes
    
    Directories count wrong for group #4768 (0, counted=32).
    Fix? yes
    
    Free inodes count wrong for group #4784 (512, counted=393).
    Fix? yes
    
    Directories count wrong for group #4784 (0, counted=32).
    Fix? yes
    
    Free inodes count wrong for group #4800 (512, counted=412).
    Fix? yes
    
    Directories count wrong for group #4800 (0, counted=32).
    Fix? yes
    
    Free inodes count wrong for group #4816 (512, counted=375).
    Fix? yes
    
    Directories count wrong for group #4816 (0, counted=32).
    Fix? yes
    
    Free inodes count wrong for group #4832 (512, counted=384).
    Fix? yes
    
    Directories count wrong for group #4832 (0, counted=32).
    Fix? yes
    
    Free inodes count wrong for group #4848 (512, counted=384).
    Fix? yes
    
    Directories count wrong for group #4848 (0, counted=32).
    Fix? yes
    
    Free inodes count wrong for group #4864 (512, counted=384).
    Fix? yes
    
    Directories count wrong for group #4864 (0, counted=32).
    Fix? yes
    
    Free inodes count wrong for group #4880 (512, counted=384).
    Fix? yes
    
    Directories count wrong for group #4880 (0, counted=32).
    Fix? yes
    
    Free inodes count wrong for group #4896 (512, counted=384).
    Fix? yes
    
    Directories count wrong for group #4896 (0, counted=32).
    Fix? yes
    
    Free inodes count wrong for group #4912 (512, counted=384).
    Fix? yes
    
    Directories count wrong for group #4912 (0, counted=32).
    Fix? yes
    
    Free inodes count wrong for group #4928 (512, counted=385).
    Fix? yes
    
    Directories count wrong for group #4928 (0, counted=32).
    Fix? yes
    
    Free inodes count wrong for group #4944 (512, counted=384).
    Fix? yes
    
    Directories count wrong for group #4944 (0, counted=32).
    Fix? yes
    
    Free inodes count wrong for group #4960 (512, counted=384).
    Fix? yes
    
    Directories count wrong for group #4960 (0, counted=32).
    Fix? yes
    
    Free inodes count wrong for group #4976 (512, counted=384).
    Fix? yes
    
    Directories count wrong for group #4976 (0, counted=32).
    Fix? yes
    
    Free inodes count wrong for group #4992 (512, counted=384).
    Fix? yes
    
    Directories count wrong for group #4992 (0, counted=32).
    Fix? yes
    
    Free inodes count wrong for group #5008 (512, counted=387).
    Fix? yes
    
    Directories count wrong for group #5008 (0, counted=32).
    Fix? yes
    
    Free inodes count wrong for group #5024 (512, counted=457).
    Fix? yes
    
    Directories count wrong for group #5024 (0, counted=23).
    Fix? yes
    
    Free inodes count wrong (6553588, counted=6551213).
    Fix? yes
    
    
    /dev/sdb5: ***** FILE SYSTEM WAS MODIFIED *****
    /dev/sdb5: 2387/6553600 files (0.3% non-contiguous), 1749101/104857600 blocks
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# fsck -y /dev/sdb5                        #让其自动修复文件系统
    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb5
    tune2fs 1.42.9 (28-Dec-2013)
    Filesystem volume name:   <none>
    Last mounted on:          <not available>
    Filesystem UUID:          0e1581cf-51a9-4f5a-b1ad-635ac3364578
    Filesystem magic number:  0xEF53
    Filesystem revision #:    1 (dynamic)
    Filesystem features:      has_journal ext_attr resize_inode dir_index filetype extent 64bit flex_bg sparse_super huge_file uninit_bg dir_nlink extra_isize
    Filesystem flags:         signed_directory_hash 
    Default mount options:    user_xattr acl
    Filesystem state:         clean
    Errors behavior:          Continue
    Filesystem OS type:       Linux
    Inode count:              6553600
    Block count:              104857600
    Reserved block count:     104857
    Free blocks:              103108499
    Free inodes:              6551213
    First block:              1
    Block size:               1024
    Fragment size:            1024
    Group descriptor size:    64
    Reserved GDT blocks:      256
    Blocks per group:         8192
    Fragments per group:      8192
    Inodes per group:         512
    Inode blocks per group:   128
    Flex block group size:    16
    Filesystem created:       Wed May 27 06:17:57 2020
    Last mount time:          n/a
    Last write time:          Wed May 27 14:41:08 2020
    Mount count:              0
    Maximum mount count:      -1
    Last checked:             Wed May 27 14:39:37 2020
    Check interval:           0 (<none>)
    Lifetime writes:          94 MB
    Reserved blocks uid:      0 (user root)
    Reserved blocks gid:      0 (group root)
    First inode:              11
    Inode size:              256
    Required extra isize:     28
    Desired extra isize:      28
    Journal inode:            8
    Default directory hash:   half_md4
    Directory Hash Seed:      c9f747cb-080f-47b7-9af2-4b82205c6094
    Journal backup:           inode blocks
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# tune2fs -l /dev/sdb5                      #文件系统修复成功啦~
    [root@yinzhengjie.com ~]# mount /dev/sdb5 /mnt                      #文件系统修复成功就可以再次挂载啦~
    [root@yinzhengjie.com ~]# 
    [root@yinzhengjie.com ~]# ll /mnt/                             #Duang~我们发现文件系统的确是好使了,但是之前保存的数据已经全部丢失啦!因此,生产环境中一定要做好备份哟~
    total 1
    drwx------ 3 root root 1024 May 27 14:39 lost+found
    [root@yinzhengjie.com ~]# 

    八.挂载文件系统

      博主推荐阅读:
          https://www.cnblogs.com/yinzhengjie/p/12828901.html
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  • 原文地址:https://www.cnblogs.com/yinzhengjie/p/12820088.html
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