LVM-相关指令

存储

一、查看信息

pvscan

首先查看物理卷情况：

[root@PBSNFS01 ~]# pvscan 
  PV /dev/emcpowera    VG vg_nfs   lvm2 [2.93 TiB / 0    free]
  PV /dev/emcpowerb1   VG vg_nfs   lvm2 [1.04 TiB / 0    free]
  PV /dev/emcpowerc1   VG vg_nfs   lvm2 [1.04 TiB / 0    free]
  PV /dev/emcpowerd1   VG vg_nfs   lvm2 [1.04 TiB / 0    free]
  Total: 4 [6.06 TiB] / in use: 4 [6.06 TiB] / in no VG: 0 [0   ]

http://www.cnblogs.com/kerrycode/p/4569515.html

所谓的安全移除：

[root@PBSNFS01 ~]# vgchange -a n vg_data
  ...
  0 logical volume(s) in volume group "vg_data" now active

[root@PBSNFS01 ~]# vgremove vg_data
  ...
  WARNING: 3 physical volumes are currently missing from the system.
Do you really want to remove volume group "vg_data" containing 1 logical volumes? [y/n]: y
  Logical volume "lv_data" successfully removed
  Volume group "vg_data" not found, is inconsistent or has PVs missing.
  Consider vgreduce --removemissing if metadata is inconsistent.

vgscan

查看卷组情况：

[root@PBSNFS01 ~]# vgscan
  Reading all physical volumes.  This may take a while...
  Found volume group "vg_nfs" using metadata type lvm2

[root@PBSNFS01 ~]# vgs
  VG     #PV #LV #SN Attr   VSize VFree
  vg_nfs   4   1   0 wz--n- 6.06t    0

lvscan

[root@PBSNFS01 ~]# lvscan
  ACTIVE            '/dev/vg_nfs/lv_nfs' [6.06 TiB] inherit

二、进行扩容

http://www.cnblogs.com/mchina/p/linux-centos-logical-volume-manager-lvm.html

[root@PBSNFS01 ~]# vgs
  VG     #PV #LV #SN Attr   VSize VFree
  vg_nfs   4   1   0 wz--n- 6.06t    0

能够看到，卷组vg_nfs上面已经没有空闲空间了。这时我们首先就需要对卷组进行扩容。最常用方案是增加PV至现有的卷组。

企业案例

审单图片的“NFS”服务器容量已满，需要进行扩容。下面是扩容前的情况：

[root@PBSNFS01 ~]# pvscan 
  PV /dev/emcpowera    VG vg_nfs   lvm2 [2.93 TiB / 0    free]
  PV /dev/emcpowerb1   VG vg_nfs   lvm2 [1.04 TiB / 0    free]
  PV /dev/emcpowerc1   VG vg_nfs   lvm2 [1.04 TiB / 0    free]
  PV /dev/emcpowerd1   VG vg_nfs   lvm2 [1.04 TiB / 0    free]
  Total: 4 [6.06 TiB] / in use: 4 [6.06 TiB] / in no VG: 0 [0   ]

治国同志已经提前为该服务器分配了一块盘，我们需要进行扫描，以便系统能够识别到新的硬盘设备。

[root@PBSNFS01 ~]# ls /sys/class/fc_host
# 会看到host1-host4，因而需要对这四个host进行扫描操作：
echo "- - -" > /sys/class/scsi_host/host1/scan
echo "- - -" > /sys/class/scsi_host/host2/scan
echo "- - -" > /sys/class/scsi_host/host3/scan
echo "- - -" > /sys/class/scsi_host/host4/scan    # 耗时大概五分钟，就能够将设备扫描出来，但是最后这条指令会卡死。

扫描完毕后（未执行其他操作）的情况：

[root@PBSNFS01 ~]# pvscan
  Couldn't find device with uuid 7EzxJZ-iWPC-3eFF-Cows-LthP-AwiE-lUdeXK.'
  Couldn't find device with uuid aUQ2oC-JRUz-l6xl-CwRj-idPs-WFQT-ikvhLG.'
  Couldn't find device with uuid yeZuAV-ciGH-w7AL-p3Gn-0akv-gWxM-fyRjKA.'
  PV /dev/emcpowere1   VG vg_data   lvm2 [1.04 TiB / 0    free]
  PV unknown device    VG vg_data   lvm2 [1.04 TiB / 0    free]
  PV unknown device    VG vg_data   lvm2 [1.04 TiB / 0    free]
  PV unknown device    VG vg_data   lvm2 [1.04 TiB / 0    free]
  PV /dev/emcpowera    VG vg_nfs    lvm2 [2.93 TiB / 0    free]
  PV /dev/emcpowerb1   VG vg_nfs    lvm2 [1.04 TiB / 0    free]
  PV /dev/emcpowerc1   VG vg_nfs    lvm2 [1.04 TiB / 0    free]
  PV /dev/emcpowerd1   VG vg_nfs    lvm2 [1.04 TiB / 0    free]
  Total: 8 [10.23 TiB] / in use: 8 [10.23 TiB] / in no VG: 0 [0   ]

说明新增的设备中携带了之前的“LVM”信息，并且是残缺的信息，因而首先需要将Unknow状态的PV从该无用VG中移除，最后再将该无用的VG移除。

# 移除未知或已丢失的卷组：
[root@PBSNFS01 ~]# vgreduce --removemissing vg_data
  Couldn't find device with uuid 7EzxJZ-iWPC-3eFF-Cows-LthP-AwiE-lUdeXK.'
  Couldn't find device with uuid aUQ2oC-JRUz-l6xl-CwRj-idPs-WFQT-ikvhLG.'
  Couldn't find device with uuid yeZuAV-ciGH-w7AL-p3Gn-0akv-gWxM-fyRjKA.'
  Wrote out consistent volume group vg_data

执行完毕后该无用卷组里面就只剩下一个物理卷了，因而要将其进行安全移除：

[root@PBSNFS01 ~]# vgchange -a n vg_data
  0 logical volume(s) in volume group "vg_data" now active

最后，移除该无用的卷组：

[root@PBSNFS01 ~]# vgremove vg_data
  Volume group "vg_data" successfully removed

移除完毕后，再次查看物理卷信息：

[root@PBSNFS01 ~]# pvs
  PV              VG     Fmt  Attr PSize PFree
  /dev/emcpowera  vg_nfs lvm2 a--  2.93t    0 
  /dev/emcpowerb1 vg_nfs lvm2 a--  1.04t    0 
  /dev/emcpowerc1 vg_nfs lvm2 a--  1.04t    0 
  /dev/emcpowerd1 vg_nfs lvm2 a--  1.04t    0 
  /dev/emcpowere1        lvm2 ---  1.04t 1.04t
# 不用再执行创建物理卷的操作，因为 emcpowere1 本身已经是个物理卷了。
# 直接对卷组进行扩容：
[root@PBSNFS01 ~]# vgextend vg_nfs /dev/emcpowere1
  Volume group "vg_nfs" successfully extended

卷组扩容完毕后再对逻辑卷扩容：

[root@PBSNFS01 ~]# lvextend -l +100%FREE /dev/mapper/vg_nfs-lv_nfs
  Size of logical volume vg_nfs/lv_nfs changed from 6.06 TiB (1588245 extents) to 7.10 TiB (1861663 extents).
  Logical volume lv_nfs successfully resized

空间扩容完毕后需要执行“resize”操作，耗时比较长，请耐心等待：

[root@PBSNFS01 ~]# resize2fs /dev/mapper/vg_nfs-lv_nfs
resize2fs 1.41.12 (17-May-2010)
Filesystem at /dev/mapper/vg_nfs-lv_nfs is mounted on /home/app/images; on-line resizing required
old desc_blocks = 388, new_desc_blocks = 455
Performing an on-line resize of /dev/mapper/vg_nfs-lv_nfs to 1906342912 (4k) blocks.
The filesystem on /dev/mapper/vg_nfs-lv_nfs is now 1906342912 blocks long.

至此，扩容完毕。