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如何安全的删除Linux LVM中的PV物理卷(硬盘或分区)

情况介绍:

  一、由于硬盘或者分区的操作方式其实都一样,所以我这里就以分区为例。

  二、/home分区2.6G,由如下pv组成:

  /dev/sda5 100M

  /dev/sda6 200M

  /dev/sda7 300M

  /dev/sda8 400M

  /dev/sda9 500M

  /dev/sda10 600M

  /dev/sda11 500M

  很碎对吧?^_^因为测试。

  三、随机写了一堆文件进去,用量达到了2G,空闲500M

  四、准备将sda6这个200M的PV卸掉(卸掉的容量必须小于空闲容量)

  好了开始具体操作了。

  卸载分区(缩小操作必须卸载才能进行):

  umount /home

  缩小分区:

  e2fsck -f /dev/liuhg_disk/home

  resize2fs /dev/liuhg_disk/home 2200M

  首先将分区缩小到2200M这是为了给sda6腾出空间,sda6为200M,而我腾出了400M,因此应该是足够的。

  缩小逻辑卷:

  lvreduce -L 2200M /dev/liuhg_disk/home

  分区缩小了用到的逻辑卷也要随着缩小,并查看PV使用的状态:

  pvdisplay -m

  显示如下:

  --- Physical volume ---

  PV Name /dev/sda5

  VG Name liuhg_disk

  PV Size 103.26 MiB / not usable 3.26 MiB

  Allocatable yes (but full)

  PE Size 4.00 MiB

  Total PE 25

  Free PE 0

  Allocated PE 25

  PV UUID 5lnx52-b4jc-OOfZ-f2QA-ttdQ-DZeD-Ce3rb3

  --- Physical Segments ---

  Physical extent 0 to 24:

  Logical volume /dev/liuhg_disk/home

  Logical extents 0 to 24

  --- Physical volume ---

  PV Name /dev/sda6

  VG Name liuhg_disk

  PV Size 203.92 MiB / not usable 3.92 MiB

  Allocatable yes (but full)

  PE Size 4.00 MiB

  Total PE 50

  Free PE 0 <-----太悲剧了,sda6里写满了数据一点不剩

  Allocated PE 50 <-----这50PE的数据要挪走才行,否则数据就丢了,并且存放的地方也必须是连续的至少50PE

  PV UUID S2ane6-nlFG-uSNR-35NP-Yxa6-cXRb-r8E8mK

  --- Physical Segments ---

  Physical extent 0 to 49:

  Logical volume /dev/liuhg_disk/home

  Logical extents 25 to 74

  --- Physical volume ---

  PV Name /dev/sda7

  VG Name liuhg_disk

  PV Size 305.89 MiB / not usable 1.89 MiB

  Allocatable yes

  PE Size 4.00 MiB

  Total PE 76

  Free PE 76 <---这个分区有76个空余,因此预计装那50个是不会有问题的

  Allocated PE 0

  PV UUID 9CFnlx-CAEw-CSul-Rig9-FiCN-zK0a-oGmTEP

  --- Physical Segments ---

  Physical extent 0 to 75:

  FREE

  --- Physical volume ---

  PV Name /dev/sda8

  VG Name liuhg_disk

  PV Size 407.87 MiB / not usable 3.87 MiB

  Allocatable yes

  PE Size 4.00 MiB

  Total PE 101

  Free PE 60

  Allocated PE 41

  PV UUID X0I8p0-x2xr-2xLG-QQD4-jbtS-3C4i-xPn4Bl

  --- Physical Segments ---

  Physical extent 0 to 40:

  Logical volume /dev/liuhg_disk/home

  Logical extents 471 to 511

  Physical extent 41 to 100:

  FREE

  --- Physical volume ---

  PV Name /dev/sda9

  VG Name liuhg_disk

  PV Size 509.84 MiB / not usable 1.84 MiB

  Allocatable yes (but full)

  PE Size 4.00 MiB

  Total PE 127

  Free PE 0

  Allocated PE 127

  PV UUID avJQaA-oMKt-NEoJ-ojBK-2Csc-1dca-1mh6Ue

  --- Physical Segments ---

  Physical extent 0 to 126:

  Logical volume /dev/liuhg_disk/home

  Logical extents 225 to 351

  --- Physical volume ---

  PV Name /dev/sda10

  VG Name liuhg_disk

  PV Size 603.98 MiB / not usable 3.98 MiB

  Allocatable yes (but full)

  PE Size 4.00 MiB

  Total PE 150

  Free PE 0

  Allocated PE 150

  PV UUID JlMIAF-A49n-M6HA-ZLXf-d8nS-pfZr-YeQsKT

  --- Physical Segments ---

  Physical extent 0 to 149:

  Logical volume /dev/liuhg_disk/home

  Logical extents 75 to 224

  --- Physical volume ---

  PV Name /dev/sda11

  VG Name liuhg_disk

  PV Size 478.47 MiB / not usable 2.47 MiB

  Allocatable yes (but full)

  PE Size 4.00 MiB

  Total PE 119

  Free PE 0

  Allocated PE 119

  PV UUID xnHJNA-tDVx-dryX-KM1x-g96Y-sptI-9iUOcU

  --- Physical Segments ---

  Physical extent 0 to 118:

  Logical volume /dev/liuhg_disk/home

  Logical extents 352 to 470

  将sda6设置为离线状态:

  pvchange -xn /dev/sda6

  使用pvdisplay -m

  显示如下:

  ……

  --- Physical volume ---

  PV Name /dev/sda6

  VG Name liuhg_disk

  PV Size 203.92 MiB / not usable 3.92 MiB

  Allocatable NO <-----表示已经关闭了该PV

  PE Size 4.00 MiB

  Total PE 50

  Free PE 0

  Allocated PE 50

  PV UUID S2ane6-nlFG-uSNR-35NP-Yxa6-cXRb-r8E8mK

  ……

  将sda6的数据移走:

  pvmove -i 1 /dev/sda6

  -i 1是每1秒钟报告一次数据迁移的进度。

  [root@liuhg /]# pvmove -i 1 /dev/sda6

  /dev/sda6: Moved: 38.0%

  /dev/sda6: Moved: 84.0%

  /dev/sda6: Moved: 100.0%

  重新用pvdisplay -m

  显示如下:

  ……

  --- Physical volume ---

  PV Name /dev/sda6

  VG Name liuhg_disk

  PV Size 203.92 MiB / not usable 3.92 MiB

  Allocatable NO

  PE Size 4.00 MiB

  Total PE 50

  Free PE 50 <----显示完全空闲和Total PE数一致

  Allocated PE 0

  PV UUID S2ane6-nlFG-uSNR-35NP-Yxa6-cXRb-r8E8mK

  ……

  从卷组里把sda6删除:

  [root@liuhg /]# vgreduce liuhg_disk /dev/sda6

  Removed "/dev/sda6" from volume group "liuhg_disk"

  pvdisplay -m再看看吧:

  --- NEW Physical volume --- <-----还告诉你这是一个新的PV ^_^

  PV Name /dev/sda6

  VG Name <-----空了

  PV Size 203.92 MiB

  Allocatable NO

  PE Size 0

  Total PE 0

  Free PE 0

  Allocated PE 0

  PV UUID S2ane6-nlFG-uSNR-35NP-Yxa6-cXRb-r8E8mK

  到此vgdisplay -v能看到已经没有了/dev/sda6了。重新挂载/home

  [root@liuhg /]# mount /dev/liuhg_disk/home /home

  [root@liuhg /]# df -h

  Filesystem Size Used Avail Use% Mounted on

  /dev/sda1 2.0G 546M 1.3G 30% /

  tmpfs 504M 0 504M 0% /dev/shm

  /dev/mapper/liuhg_disk-home

  2.2G 1.8G 42M 98% /home

  进去看看数据,一个都没丢。

(责任编辑:IT)