Linux LVM学习总结——删除物理卷

本篇介绍LVM管理中的命令vgreduce, pvremove。其实前面几篇中以及有所涉及。

   vgreduce：通过删除LVM卷组中的物理卷来减少卷组容量。注意：不能删除LVM卷组中剩余的最后一个物理卷

   pvremove: 用于删除一个存在的物理卷。使用pvremove指令删除物理卷时，它将LVM分区上的物理卷信息删除，使其不再被视为一个物理卷。

在删除物理卷PV之前，必须将服务器的分区信息、卷组信息、物理卷信息、逻辑卷信息都掌握清楚，避免出现失误或误操作。

[root@localhost ~]# fdisk -l

Disk /dev/sda: 128.8 GB, 128849018880 bytes
255 heads, 63 sectors/track, 15665 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          13      104391   83  Linux
/dev/sda2              14       10443    83778975   8e  Linux LVM
/dev/sda3           10444       15665    41945715   83  Linux
[root@localhost ~]# vgscan
  Reading all physical volumes.  This may take a while...
  Found volume group "VolGroup00" using metadata type lvm2
[root@localhost ~]# pvscan
  PV /dev/sda2   VG VolGroup00   lvm2 [79.88 GB / 0    free]
  PV /dev/sda3   VG VolGroup00   lvm2 [40.00 GB / 40.00 GB free]
  Total: 2 [119.88 GB] / in use: 2 [119.88 GB] / in no VG: 0 [0   ]
[root@localhost ~]# pvdisplay
  --- Physical volume ---
  PV Name               /dev/sda2
  VG Name               VolGroup00
  PV Size               79.90 GB / not usable 23.41 MB
  Allocatable           yes (but full)
  PE Size (KByte)       32768
  Total PE              2556
  Free PE               0
  Allocated PE          2556
  PV UUID               YGtB2J-ZKJr-mV62-NluQ-2DGy-vuUT-cCc1lo

  --- Physical volume ---
  PV Name               /dev/sda3
  VG Name               VolGroup00
  PV Size               40.00 GB / not usable 2.61 MB
  Allocatable           yes
  PE Size (KByte)       32768
  Total PE              1280
  Free PE               1280
  Allocated PE          0
  PV UUID               wsnv13-7j1H-SH8q-hl6k-HpNc-x4WU-gM7LzW

[root@localhost ~]# lvscan
  ACTIVE            '/dev/VolGroup00/LogVol00' [77.91 GB] inherit
  ACTIVE            '/dev/VolGroup00/LogVol01' [1.97 GB] inherit
[root@localhost ~]# lvs
  LV       VG         Attr   LSize  Origin Snap%  Move Log Copy%  Convert
  LogVol00 VolGroup00 -wi-ao 77.91G
  LogVol01 VolGroup00 -wi-ao  1.97G

vgreduce参数：

-a：如果命令行中没有指定要删除的物理卷，则删除所有的空物理卷；

--removemissing：删除卷组中丢失的物理卷，使卷组恢复正常状态。

[root@localhost ~]# vgreduce VolGroup00 /dev/sda3

Removed "/dev/sda3" from volume group "VolGroup00"

[root@localhost ~]#

[root@localhost ~]# pvscan
  PV /dev/sda2   VG VolGroup00      lvm2 [79.88 GB / 0    free]
  PV /dev/sda3                      lvm2 [40.00 GB]
  Total: 2 [119.88 GB] / in use: 1 [79.88 GB] / in no VG: 1 [40.00 GB]
[root@localhost ~]# pvs
  PV         VG         Fmt  Attr PSize  PFree
  /dev/sda2  VolGroup00 lvm2 a-   79.88G     0
  /dev/sda3             lvm2 a-   40.00G 40.00G
[root@localhost ~]# pvremove /dev/sda3
  Labels on physical volume "/dev/sda3" successfully wiped
[root@localhost ~]# pvscan
  PV /dev/sda2   VG VolGroup00   lvm2 [79.88 GB / 0    free]
  Total: 1 [79.88 GB] / in use: 1 [79.88 GB] / in no VG: 0 [0   ]