• Oracle Linux 6.4 LVM中误删VG之恢复过程


     

    一、项目背景描述
    1、OSS现网测试数据库因大量小事物频繁提交运行非常缓慢。经分析为DS3950存储所在磁盘I/O存在瓶颈,大量等待事件,性能受限。另外,开发同事没有优化意识,没将小事物做成批量提交方式。
    2、在DS3950上,9块600G硬盘(8块+1块热备)做了RAID5阵列,lun01,lun02,lun03,lun04,均为200G,映射给OSS数据库服务器使用。
    3、在操作系统上,lun01,lun02构成了vg_ossdb卷组,vg_ossdb下只有一个LV--lvoradata挂载在/oradata上。最近因数据增长过快,又将lun03,lun04以vgextend方式扩到了vg_ossdb卷组中去,但尚未扩大lvoradata。
    4、在数据库上,Oracle软件安装在本地磁盘/oracle上,数据库安装在/oradata上。


    二、项目改造计划及步骤
    1、停掉数据库,将/oradata目录全备份到另一台备用PC机器上。
    2、由于DS3950存储空闲空很大,可修改其阵列级别从RAID5变为RAID10。
    3、由于lun03,lun04尚未使用,领导要求先从vg_ossdb中移除lun03,lun04,并在存储上unmap掉,便于阵列级别变更。
    4、由DBA优化SQL,将小事物尽量做到批量提交方式。


    三、系统环境及数据版本说明
    [root@ol64 /]# cat /etc/issue
    Oracle Linux Server release 6.4
    Kernel on an m


    [root@ol64 /]# uname -a
    Linux ol64.com 2.6.39-400.17.1.el6uek.x86_64 #1 SMP Fri Feb 22 18:16:18 PST 2013 x86_64 x86_64 x86_64 GNU/Linux


    SQL> select * from v$version;
    BANNER
    --------------------------------------------------------------------------------
    Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
    PL/SQL Release 11.2.0.4.0 - Production
    CORE 11.2.0.4.0 Production
    TNS for Linux: Version 11.2.0.4.0 - Production
    NLSRTL Version 11.2.0.4.0 - Production


    四、改造过程中因误用vgremove将vg_ossdb卷组删除,而其本意是想用vgreduce移除/dev/sdd,/dev/sde的。
    [root@ol64 /]# umount /oradata/ #卸载文件系统
    [root@ol64 /]# vgchange -an /dev/vg_ossdb #将卷组置于非激活状态
    0 logical volume(s) in volume group "vg_ossdb" now active
    [root@ol64 /]# vgremove vg_ossdb /dev/sdb /dev/sdc /dev/sdd /dev/sde #误用vgremove命令删除了vg_ossdb
    Do you really want to remove volume group "vg_ossdb" containing 1 logical volumes? [y/n]: y
    Do you really want to remove active logical volume lvoradata? [y/n]: y
    Logical volume "lvoradata" successfully removed
    Volume group "vg_ossdb" successfully removed
    Volume group "sdb" not found
    Volume group "sdc" not found
    Volume group "sdd" not found
    Volume group "sde" not found
    ##################################################################
    正确的操作应该是用vgreduce命令从vg_ossdb中移除/dev/sdd和/dev/sde
    [root@ol64 /]# vgreduce vg_ossdb /dev/sdd
    Removed "/dev/sdd" from volume group "vg_ossdb"
    [root@ol64 /]# vgreduce vg_ossdb /dev/sde
    Removed "/dev/sde" from volume group "vg_ossdb"
    #################################################################
    再用pvremove命令移除/dev/sdd和/dev/sde
    [root@ol64 ~]# pvremove /dev/sdd
    Labels on physical volume "/dev/sdd" successfully wiped
    [root@ol64 ~]# pvremove /dev/sde
    Labels on physical volume "/dev/sde" successfully wiped


    [root@ol64 ~]# pvdisplay #发现/dev/sdb和/dev/sdc所在VG Name为空,冒汗ing.
    --- Physical volume ---
    PV Name /dev/sda2
    VG Name vg_ol64
    PV Size 199.51 GiB / not usable 3.00 MiB
    Allocatable yes
    PE Size 4.00 MiB
    Total PE 51074
    Free PE 33660
    Allocated PE 17414
    PV UUID 0dyB8L-p7ZM-Mkcw-76ae-DXPh-U6zg-9kIQ8z


    "/dev/sdb" is a new physical volume of "200.00 GiB"
    --- NEW Physical volume ---
    PV Name /dev/sdb
    VG Name
    PV Size 200.00 GiB
    Allocatable NO
    PE Size 0
    Total PE 0
    Free PE 0
    Allocated PE 0
    PV UUID Ui9wea-II1q-KOx0-96pA-4epf-9hlc-4NFDJF


    "/dev/sdc" is a new physical volume of "200.00 GiB"
    --- NEW Physical volume ---
    PV Name /dev/sdc
    VG Name
    PV Size 200.00 GiB
    Allocatable NO
    PE Size 0
    Total PE 0
    Free PE 0
    Allocated PE 0
    PV UUID 4VKCJ9-G6kL-QJgg-Titf-UNA8-d3QZ-ZTES3P


    [root@ol64 ~]# vgscan #vgscan时找不到vg_ossdb信息,心跳加速,冒汗ing.
    Reading all physical volumes. This may take a while...
    Found volume group "vg_ol64" using metadata type lvm2


    [root@ol64 ~]# lvscan #lvscan时找不到lvoradata信息,大脑一片空白,快要晕倒.
    ACTIVE '/dev/vg_ol64/lvopt' [10.01 GiB] inherit
    ACTIVE '/dev/vg_ol64/lvroot' [40.01 GiB] inherit
    ACTIVE '/dev/vg_ol64/lvswap' [8.00 GiB] inherit
    ACTIVE '/dev/vg_ol64/lvhome' [10.01 GiB] inherit


    我怎么会用vgremove命令??完了!!!vg_ossdb被我误删除了。赶紧google和baidu上搜索vg被删除后如何恢复,可压根找不到相关资料。冷静下来后开始思考/etc/lvm/目录下各文件用途。

    五、VG恢复思路
    1、在/etc/lvm/存放着LVM的配置、归档、备份等信息。
    [root@ol64 ~]# ls -l /etc/lvm
    total 52
    drwx------. 2 root root 4096 Nov 18 08:30 archive
    drwx------. 2 root root 4096 Nov 18 08:30 backup
    drwx------. 2 root root 4096 Feb 24 2013 cache
    -rw-r--r--. 1 root root 37554 Feb 24 2013 lvm.conf


    2、在/etc/lvm/backup/下存放着vg的备份信息,但我在操作vg_ossdb之前没有备份其信息到其它目录。
    [root@ol64 lvm]# ls /etc/lvm/backup/
    total 4
    -rw-------. 1 root root 2575 Nov 12 09:09 vg_ol64


    3、在 /etc/lvm/archive/下存放着VG及LV调整前的归档信息,即VG变更或LV变更前均会备份当前信息。
    [root@ol64 ~]# ls -l /etc/lvm/archive/
    total 32
    -rw-------. 1 root root 2576 Nov 12 09:09 vg_ol64_00000-1722993391.vg
    -rw-------. 1 root root 883 Nov 18 08:03 vg_ossdb_00000-2033719300.vg
    -rw-------. 1 root root 883 Nov 18 08:04 vg_ossdb_00001-1635801039.vg
    -rw-------. 1 root root 1122 Nov 18 08:05 vg_ossdb_00002-1283186973.vg
    -rw-------. 1 root root 883 Nov 18 08:05 vg_ossdb_00003-1708919759.vg
    -rw-------. 1 root root 1139 Nov 18 08:05 vg_ossdb_00004-18964421.vg
    -rw-------. 1 root root 1728 Nov 18 08:30 vg_ossdb_00005-533258090.vg
    -rw-------. 1 root root 1131 Nov 18 08:30 vg_ossdb_00006-1987723911.vg
    备注:使用vgcreate、vgreduce、vgremove、lvcreate、lvreduce、lvremove等命令时均会生成新的归档信息


    4、利用vgcfgrestore命令恢复误删除的VG
    [root@ol64 archive]# vgcfgrestore -f /etc/lvm/archive/vg_ossdb_00001-1635801039.vg vg_ossdb
    Restored volume group vg_ossdb
    [root@ol64 archive]# pvdisplay
    --- Physical volume ---
    PV Name /dev/sdb
    VG Name vg_ossdb
    PV Size 200.00 GiB / not usable 4.00 MiB
    Allocatable yes
    PE Size 4.00 MiB
    Total PE 51199
    Free PE 51199
    Allocated PE 0
    PV UUID Ui9wea-II1q-KOx0-96pA-4epf-9hlc-4NFDJF


    --- Physical volume ---
    PV Name /dev/sda2
    VG Name vg_ol64
    PV Size 199.51 GiB / not usable 3.00 MiB
    Allocatable yes
    PE Size 4.00 MiB
    Total PE 51074
    Free PE 33660
    Allocated PE 17414
    PV UUID 0dyB8L-p7ZM-Mkcw-76ae-DXPh-U6zg-9kIQ8z


    "/dev/sdc" is a new physical volume of "200.00 GiB"
    --- NEW Physical volume ---
    PV Name /dev/sdc
    VG Name
    PV Size 200.00 GiB
    Allocatable NO
    PE Size 0
    Total PE 0
    Free PE 0
    Allocated PE 0
    PV UUID 4VKCJ9-G6kL-QJgg-Titf-UNA8-d3QZ-ZTES3P
    上述操作发现只有/dev/sdb在vg_ossdb卷组中了,而/dev/sdc仍然不在vg_ossdb卷组中。这说明/etc/lvm/archive/vg_ossdb_00001-1635801039.vg归档文件较旧,还没有包括/dev/sdc在vg_ossdb卷组中,继续使用下一个归档文件恢复,直到/dev/sdb、/dev/sdc均在vg_ossdb卷组中,并且卷组中包含的LV个数正确。


    [root@ol64 archive]# vgcfgrestore -f /etc/lvm/archive/vg_ossdb_00005-533258090.vg vg_ossdb
    Restored volume group vg_ossdb
    [root@ol64 archive]# vgchange -ay /dev/vg_ossdb
    1 logical volume(s) in volume group "vg_ossdb" now active
    [root@ol64 archive]# lvscan
    ACTIVE '/dev/vg_ossdb/lvoradata' [200.00 GiB] inherit
    ACTIVE '/dev/vg_ol64/lvopt' [10.01 GiB] inherit
    ACTIVE '/dev/vg_ol64/lvroot' [40.01 GiB] inherit
    ACTIVE '/dev/vg_ol64/lvswap' [8.00 GiB] inherit
    ACTIVE '/dev/vg_ol64/lvhome' [10.01 GiB] inherit


    [root@ol64 archive]# mount /dev/vg_ossdb/lvoradata /oradata/
    [root@ol64 archive]# ls -l /oradata/ossdb/
    total 1698340
    -rwxrwxr-x. 1 Oracle oinstall 9748480 Nov 18 08:29 control01.ctl
    -rwxrwxr-x. 1 oracle oinstall 1073742336 Nov 18 08:11 redo01.log
    -rwxrwxr-x. 1 oracle oinstall 1073742336 Nov 18 08:11 redo02.log
    -rwxrwxr-x. 1 oracle oinstall 1073742336 Nov 18 08:29 redo03.log
    -rwxrwxr-x. 1 oracle oinstall 2147516416 Nov 18 08:29 sysaux01.dbf
    -rwxrwxr-x. 1 oracle oinstall 2147516416 Nov 18 08:29 system01.dbf
    -rwxrwxr-x. 1 oracle oinstall 8388640768 Nov 18 06:38 temp01.dbf
    -rwxrwxr-x. 1 oracle oinstall 17179901952 Nov 18 08:29 undotbs01.dbf
    -rwxrwxr-x. 1 oracle oinstall 17179901952 Nov 18 08:29 users01.dbf
    //省略....
    启动数据库,一切正常。

    总结:在对VG做变更时,切记先用vgcfgbackup备份好VG的信息,避免意外。
    [root@ol64 /]# vgcfgbackup -f /home/vg_ossdb.backup vg_ossdb
    尽管本次操作并未造成损失,但惊醒了我。作为系统管理员,每一步操作都必须深思熟虑。切记,操作权限越大,承担责任也越大! 
     
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  • 原文地址:https://www.cnblogs.com/pipci/p/11477184.html
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