LVM – LV 指令

lvcreate 從 VG 中建立 LV
# lvcreate -L <size> [-n <lv name>] <vg>
# lvcreate -L 50M -n v1 diskvg
  Rounding up size to full physical extent 52.00 MiB
  Logical volume “v1” created
# lvcreate -L 150M -n v2 diskvg
  Rounding up size to full physical extent 152.00 MiB
  Logical volume “v2” created
# lvcreate -L 250M -n v3 diskvg
  Rounding up size to full physical extent 252.00 MiB
  Logical volume “v3” created
以 32 個 PE 空間來建立 LV
# lvcreate -l 32 -n v4 diskvg

lvdisplay 顯示 LV 資訊
# lvdisplay /dev/diskvg/v1
  — Logical volume —
  LV Name                /dev/diskvg/v1
  VG Name                diskvg
  LV UUID                50dHxI-bwNi-xksv-P4rS-XS1W-suNi-z3ljTc
  LV Write Access        read/write
  LV Status              available
  # open                 0
  LV Size                52.00 MiB
  Current LE             13
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  – currently set to     1024
  Block device           253:0

[@more@]lvscan 用來掃描系統中所有 LV 的資訊
# lvscan
  inactive          ‘/dev/diskvg/v1’ [52.00 MiB] inherit
  inactive          ‘/dev/diskvg/v2’ [152.00 MiB] inherit
  inactive          ‘/dev/diskvg/v3’ [252.00 MiB] inherit
  ACTIVE            ‘/dev/diskvg/v4’ [128.00 MiB] inherit

lvextend 用來放大 Logical volume 的大小
# lvextend {-L [+]LogicalVolumeSize | -1 [+]LogicalExtentsNumber } <lv>
把 v1 空間加大 100M
# lvextend -L +100M /dev/diskvg/v1
  Extending logical volume v1 to 152.00 MiB
  Logical volume v1 successfully resized
# lvdisplay /dev/diskvg/v1
  — Logical volume —
  LV Name                /dev/diskvg/v1
  VG Name                diskvg
  LV UUID                50dHxI-bwNi-xksv-P4rS-XS1W-suNi-z3ljTc
  LV Write Access        read/write
  LV Status              NOT available
  LV Size                152.00 MiB
  Current LE             38
  Segments               2
  Allocation             inherit
  Read ahead sectors     auto

lvremove 刪除 Logical Volume
# lvremove /dev/diskvg/v4
Do you really want to remove active logical volume v4? [y/n]: y
  Logical volume “v4” successfully removed
# lvscan
  inactive          ‘/dev/diskvg/v1’ [152.00 MiB] inherit
  inactive          ‘/dev/diskvg/v2’ [152.00 MiB] inherit
  inactive          ‘/dev/diskvg/v3’ [252.00 MiB] inherit