5-LVM逻辑卷管理

2016.6.13

LVM概述

1.PV（Physical Volume,物理卷）

1）pvscan命令

[root@test2 jason]# pvscan
  PV /dev/sda2   VG vg_jason   lvm2 [19.51 GiB / 0    free]
  Total: 1 [19.51 GiB] / in use: 1 [19.51 GiB] / in no VG: 0 [0   ]
[root@test2 jason]#

2) pvcreate命令

[root@test2 jason]# pvcreate /dev/sdb1 /dev/sdb2 /dev/sdb3
  Physical volume "/dev/sdb1" successfully created
  Physical volume "/dev/sdb2" successfully created
  dev_is_mpath: failed to get device for 8:19
  dev_is_mpath: failed to get device for 8:19
  Device /dev/sdb3 not found (or ignored by filtering).

原因分析，是sdb3是扩展分区

查看现有分区信息：

[root@test2 jason]# fdisk -l

Disk /dev/sda: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000d0a36

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          64      512000   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2              64        2611    20458496   8e  Linux LVM

Disk /dev/sdb: 85.9 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xa8f24694

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1        2612    20980858+  83  Linux
/dev/sdb2            2613        5224    20980890   83  Linux
/dev/sdb3            5225       10443    41921617+   5  Extended
/dev/sdb5            5225        5486     2104483+  82  Linux swap / Solaris
/dev/sdb6            5487        6792    10490413+  83  Linux

Disk /dev/mapper/vg_jason-lv_root: 18.8 GB, 18798870528 bytes
255 heads, 63 sectors/track, 2285 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Disk /dev/mapper/vg_jason-lv_swap: 2147 MB, 2147483648 bytes
255 heads, 63 sectors/track, 261 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

重新分配sdb3

[root@test2 jason]# fdisk /dev/sdb

WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
         switch off the mode (command 'c') and change display units to
         sectors (command 'u').

Command (m for help): t
Partition number (1-6): 3
Hex code (type L to list codes): 83
You cannot change a partition into an extended one or vice versa
Delete it first.

Command (m for help): d
Partition number (1-6): 3

Command (m for help): t
Partition number (1-4): 3
Partition 3 does not exist yet!

Command (m for help): n
Command action
   e   extended
   p   primary partition (1-4)
p
Partition number (1-4): 3
First cylinder (5225-10443, default 5225):
Using default value 5225
Last cylinder, +cylinders or +size{K,M,G} (5225-10443, default 10443):
Using default value 10443

Command (m for help): p

Disk /dev/sdb: 85.9 GB, 85899345920 bytes
255 heads, 63 sectors/track, 10443 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xa8f24694

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1               1        2612    20980858+  83  Linux
/dev/sdb2            2613        5224    20980890   83  Linux
/dev/sdb3            5225       10443    41921617+  83  Linux

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.

再次使用pvcreate命令：

[root@test2 jason]# pvcreate /dev/sdb1/ /dev/sd
sda   sda1  sda2  sdb   sdb1  sdb2  sdb3
[root@test2 jason]# pvcreate /dev/sdb1 /dev/sdb2 /dev/sdb3
  Physical volume "/dev/sdb1" successfully created
  Physical volume "/dev/sdb2" successfully created
  Physical volume "/dev/sdb3" successfully created
[root@test2 jason]#

3）pvdisplay命令

[root@test2 jason]# pvdisplay /dev/sdb3
  "/dev/sdb3" is a new physical volume of "39.98 GiB"
  --- NEW Physical volume ---
  PV Name               /dev/sdb3
  VG Name
  PV Size               39.98 GiB
  Allocatable           NO
  PE Size               0
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               UB831l-dcjr-1uGK-ZZNQ-hw4Z-SMbf-2uXZUn

[root@test2 jason]# pvdisplay /dev/sdb1
  "/dev/sdb1" is a new physical volume of "20.01 GiB"
  --- NEW Physical volume ---
  PV Name               /dev/sdb1
  VG Name
  PV Size               20.01 GiB
  Allocatable           NO
  PE Size               0
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               fvMlj2-a75t-dOui-Ye6o-VGCL-FWX2-JwQ1g2

4）pvremove命令

before remove：

[root@test2 jason]# pvscan
  PV /dev/sda2   VG vg_jason        lvm2 [19.51 GiB / 0    free]
  PV /dev/sdb1                      lvm2 [20.01 GiB]
  PV /dev/sdb2                      lvm2 [20.01 GiB]
  PV /dev/sdb3                      lvm2 [39.98 GiB]
  Total: 4 [99.51 GiB] / in use: 1 [19.51 GiB] / in no VG: 3 [80.00 GiB]
[root@test2 jason]#

removing：

错误的命令：

[root@test2 jason]# remove /dev/sdb3
bash: remove: command not found

正确的命令

[root@test2 jason]# pvremove /dev/sdb3
  Labels on physical volume "/dev/sdb3" successfully wiped
[root@test2 jason]#

after remove：

[root@test2 jason]# pvscan
  PV /dev/sda2   VG vg_jason        lvm2 [19.51 GiB / 0    free]
  PV /dev/sdb1                      lvm2 [20.01 GiB]
  PV /dev/sdb2                      lvm2 [20.01 GiB]
  Total: 3 [59.53 GiB] / in use: 1 [19.51 GiB] / in no VG: 2 [40.02 GiB]

从这里可以看出来sdb3已经被移除

LVM的管理命令

1.PV物理卷管理

2.VG卷组管理

3.LV逻辑卷管理