CentOS7.x系统根目录分区扩容

注意：扩容根分区之前，首先保证你装系统的时候选择的是LVM格式而不是标准格式

添加一块新磁盘

[root@DEV-CMDB-DB02 ~]# fdisk -l

Disk /dev/sda: 53.7 GB, 53687091200 bytes, 104857600 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x000e0945

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048     1026047      512000   83  Linux
/dev/sda2         1026048   104857599    51915776   8e  Linux LVM

Disk /dev/sdb: 107.4 GB, 107374182400 bytes, 209715200 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/mapper/centos_mb--centos7-root: 47.7 GB, 47747956736 bytes, 93257728 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes


Disk /dev/mapper/centos_mb--centos7-swap: 5368 MB, 5368709120 bytes, 10485760 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

step3. 根据以上信息，对新增加的磁盘进行分区

[root@DEV-CMDB-DB02 ~]# fdisk /dev/sdb
Welcome to fdisk (util-linux 2.23.2).

Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.

Device does not contain a recognized partition table
Building a new DOS disklabel with disk identifier 0x232defba.

Command (m for help): p

Disk /dev/sdb: 107.4 GB, 107374182400 bytes, 209715200 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x232defba

   Device Boot      Start         End      Blocks   Id  System

Command (m for help): n
Partition type:
   p   primary (0 primary, 0 extended, 4 free)
   e   extended
Select (default p): p
Partition number (1-4, default 1): 1
First sector (2048-209715199, default 2048): 
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-209715199, default 209715199): 
Using default value 209715199
Partition 1 of type Linux and of size 100 GiB is set

Command (m for help): t
Selected partition 1
Hex code (type L to list all codes): L
 Empty           24  NEC DOS         81  Minix / old Lin bf  Solaris        
 FAT12           27  Hidden NTFS Win 82  Linux swap / So c1  DRDOS/sec (FAT-
 XENIX root      39  Plan 9          83  Linux           c4  DRDOS/sec (FAT-
 XENIX usr       3c  PartitionMagic  84  OS/2 hidden C:  c6  DRDOS/sec (FAT-
 FAT16 <32M      40  Venix 80286     85  Linux extended  c7  Syrinx         
 Extended        41  PPC PReP Boot   86  NTFS volume set da  Non-FS data    
 FAT16           42  SFS             87  NTFS volume set db  CP/M / CTOS / .
 HPFS/NTFS/exFAT 4d  QNX4.x          88  Linux plaintext de  Dell Utility   
 AIX             4e  QNX4.x 2nd part 8e  Linux LVM       df  BootIt         
 AIX bootable    4f  QNX4.x 3rd part 93  Amoeba          e1  DOS access     
 a  OS/2 Boot Manag 50  OnTrack DM      94  Amoeba BBT      e3  DOS R/O        
 b  W95 FAT32       51  OnTrack DM6 Aux 9f  BSD/OS          e4  SpeedStor      
 c  W95 FAT32 (LBA) 52  CP/M            a0  IBM Thinkpad hi eb  BeOS fs        
 e  W95 FAT16 (LBA) 53  OnTrack DM6 Aux a5  FreeBSD         ee  GPT            
 f  W95 Ext'd (LBA) 54  OnTrackDM6      a6  OpenBSD         ef  EFI (FAT-12/16/
 OPUS            55  EZ-Drive        a7  NeXTSTEP        f0  Linux/PA-RISC b
 Hidden FAT12    56  Golden Bow      a8  Darwin UFS      f1  SpeedStor      
 Compaq diagnost 5c  Priam Edisk     a9  NetBSD          f4  SpeedStor      
 Hidden FAT16 <3 61  SpeedStor       ab  Darwin boot     f2  DOS secondary  
 Hidden FAT16    63  GNU HURD or Sys af  HFS / HFS+      fb  VMware VMFS    
 Hidden HPFS/NTF 64  Novell Netware  b7  BSDI fs         fc  VMware VMKCORE 
 AST SmartSleep  65  Novell Netware  b8  BSDI swap       fd  Linux raid auto
1b  Hidden W95 FAT3 70  DiskSecure Mult bb  Boot Wizard hid fe  LANstep        
1c  Hidden W95 FAT3 75  PC/IX           be  Solaris boot    ff  BBT            
1e  Hidden W95 FAT1 80  Old Minix      
Hex code (type L to list all codes): 8e
Changed type of partition 'Linux' to 'Linux LVM'

Command (m for help): p

Disk /dev/sdb: 107.4 GB, 107374182400 bytes, 209715200 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x232defba

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048   209715199   104856576   8e  Linux LVM

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

step4. 创建物理卷

[root@DEV-CMDB-DB02 ~]# pvcreate /dev/sdb1
  Physical volume "/dev/sdb1" successfully created

step5. 查看物理卷信息

[root@DEV-CMDB-DB02 ~]# pvdisplay
  --- Physical volume ---
  PV Name               /dev/sda2
  VG Name               centos_mb-centos7
  PV Size               49.51 GiB / not usable 3.00 MiB
  Allocatable           yes 
  PE Size               4.00 MiB
  Total PE              12674
  Free PE               10
  Allocated PE          12664
  PV UUID               8WbgjB-T1Lf-kqUD-qPFw-UwJu-B9Lc-GAUTUB
   
  "/dev/sdb1" is a new physical volume of "100.00 GiB"
  --- NEW Physical volume ---
  PV Name               /dev/sdb1
  VG Name               
  PV Size               100.00 GiB
  Allocatable           NO
  PE Size               0   
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               HOknRs-TnMy-wtfX-sGqD-5RK9-dk9q-ze13fj

[root@DEV-CMDB-DB02 ~]# vgdisplay
  --- Volume group ---
  VG Name               centos_mb-centos7
  System ID             
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  3
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                2
  Open LV               2
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               49.51 GiB
  PE Size               4.00 MiB
  Total PE              12674
  Alloc PE / Size       12664 / 49.47 GiB
  Free  PE / Size       10 / 40.00 MiB
  VG UUID               aN2D2P-Rk1y-wGFz-5l2I-5CcD-7s88-Z8czc7

step6. 将新增加的分区/dev/sdb1加入到根目录分区centos_mb-centos7中

[root@DEV-CMDB-DB02 ~]# vgextend centos_mb-centos7 /dev/sdb1
  Volume group "centos_mb-centos7" successfully extended

step7. 重新查看卷组信息

[root@DEV-CMDB-DB02 ~]# vgdisplay
  --- Volume group ---
  VG Name               centos_mb-centos7
  System ID             
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  4
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                2
  Open LV               2
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               149.50 GiB
  PE Size               4.00 MiB
  Total PE              38273
  Alloc PE / Size       12664 / 49.47 GiB
  Free  PE / Size       25609 / 100.04 GiB
  VG UUID               aN2D2P-Rk1y-wGFz-5l2I-5CcD-7s88-Z8czc7

step9. 进行卷扩容

[root@DEV-CMDB-DB02 ~]# lvextend -l +100%FREE /dev/mapper/centos_mb--centos7-root
  Size of logical volume centos_mb-centos7/root changed from 44.47 GiB (11384 extents) to 144.50 GiB (36993 extents).
  Logical volume root successfully resized.

step10. 调整卷分区大小

[root@DEV-CMDB-DB02 ~]# xfs_growfs /dev/mapper/centos_mb--centos7-root
meta-data=/dev/mapper/centos_mb--centos7-root isize=256    agcount=4, agsize=2914304 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=0        finobt=0
data     =                       bsize=4096   blocks=11657216, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0 ftype=0
log      =internal               bsize=4096   blocks=5692, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0
data blocks changed from 11657216 to 37880832

最后，查看磁盘信息可以看出根目录分区大小已成功扩容

[root@DEV-CMDB-DB02 ~]# df -h
Filesystem                           Size  Used Avail Use% Mounted on
/dev/mapper/centos_mb--centos7-root  145G  9.8G  135G   7% /
devtmpfs                             5.9G     0  5.9G   0% /dev
tmpfs                                5.9G   84K  5.9G   1% /dev/shm
tmpfs                                5.9G  8.9M  5.9G   1% /run
tmpfs                                5.9G     0  5.9G   0% /sys/fs/cgroup
/dev/sda1                            497M  142M  356M  29% /boot
tmpfs                                1.2G   16K  1.2G   1% /run/user/42
tmpfs                                1.2G     0  1.2G   0% /run/user/0