環境先容：

一、由于硬盤可能分區的操縱方法其實都一樣，所以我這里就以分區為例。

二、/home分區2.6G，由如下pv構成：

/dev/sda5  100M

/dev/sda6   200M

/dev/sda7   300M

/dev/sda8   400M

/dev/sda9    500M

/dev/sda10  600M

/dev/sda11  500M

很碎對吧？^_^因為測試。

三、隨機寫了一堆文件進去，用量到達了2G，空閑500M

四、籌備將sda6這個200M的PV卸掉（卸掉的容量必需小于空閑容量）

好了開始詳細操縱了。

卸載分區（縮小操縱必需卸載才氣舉辦）：

umount /home

縮小分區：

e2fsck -f /dev/liuhg_disk/home

resize2fs /dev/liuhg_disk/home 2200M

 首先將分區縮小到2200M這是為了給sda6騰出空間，sda6為200M，而我騰出了400M，因此應該是足夠的。

縮小邏輯卷：

lvreduce -L 2200M /dev/liuhg_disk/home

分區縮小了用到的邏輯卷也要跟著縮小，并查察PV利用的狀態：

pvdisplay -m

顯示如下：

    --- 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        <-----太悲劇了，sda6里寫滿了數據一點不剩
  Allocated PE          50    <-----這50PE的數據要挪走才行，不然數據就丟了，而且存放的處所也必需是持續的至少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  <---這個分區有76個空余，因此估量裝那50個是不會有問題的
  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

將sda6配置為離線狀態：

pvchange -xn /dev/sda6

利用pvdisplay -m

顯示如下：

……