LVM日常管理之（二）VG改名 & 因VG 和 LV名同时存在冲突时，如何确定 LV属于某个VG，并修正

背景介绍：

1、服务器A有两块盘，原本装CentOS7系统时采用默认安装（即使用lvm自动分区，将两块盘组成一样的分区），
2、当故障后，系统无法启动，经检查数据还在的，但是数据量比较大，若是通过网络进行数据拷贝，时间非常长，打算为其安排同样配置的服务器
3、（硬盘也是两块，并且是相同大小，系统啥的都一样也采用了默认lvm分区的形式安装），新服务器装好后，把老服务器的两块硬盘插入新服务器上，结果因lvm卷组明冲突导致系统无法正常启动

解决思路及方法：将原本两块老硬盘所组成的vg组名进行更改。

1、进入恢复或者单用户模式，或者外挂再生龙镜像进入shell模式，激活全部VG，
2、因为vg存在重名，所以只能激活一个，只有这个被激活vg上的lvm才可以被正确挂载，
3、挂载激活的lv后根据里面的内容，比如IP等信息判断当前激活这个lv是属于老硬盘内容还是说新服务器的内容
4、抱歉，这篇文章其实就一句话是有用的，“使用vgdisplay -v 确定当前激活 lv 所属的vg uuid是什么？”

[root@localhost ~]# lvscan 
  inactive          '/dev/FNK/LT' [12.00 GiB] inherit
  inactive          '/dev/FNK/LT' [12.00 GiB] inherit
[root@localhost ~]# pvscan 
  PV /dev/sdb   VG FNK             lvm2 [<8.00 GiB / 0    free]
  PV /dev/sdc   VG FNK             lvm2 [<8.00 GiB / 3.99 GiB free]
  PV /dev/sdd   VG FNK             lvm2 [<8.00 GiB / 0    free]
  PV /dev/sde   VG FNK             lvm2 [<8.00 GiB / 3.99 GiB free]
  Total: 4 [31.98 GiB] / in use: 4 [31.98 GiB] / in no VG: 0 [0   ]
[root@localhost ~]# vgchange -ay        尝试激活所有的VG
  1 logical volume(s) in volume group "FNK" now active
  device-mapper: create ioctl on FNK-LT LVM-9BwcTY5aSypz1j2paYjNBSq79W7199ioRiQ9UNPu7sfb3U8uvgXWfHjF7Rvd2zC3 failed: 设备或资源忙
  0 logical volume(s) in volume group "FNK" now active
[root@localhost ~]# lvscan              查看lv状态，要是有激活的可以进行挂载
  ACTIVE            '/dev/FNK/LT' [12.00 GiB] inherit
  inactive          '/dev/FNK/LT' [12.00 GiB] inherit
[root@localhost ~]# mount /dev/FNK/LT /tmp      挂载后自己去验证数据是否是老服务器或者新服务器的

使用vgdisplay -v确定当前所激活的vg uuid是什么，结合挂载查看到的文件，来确定要该激活的VG名字还是未激活的

[root@localhost lvm]# vgdisplay -v
  --- Volume group ---
  VG Name               FNK
  System ID             
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  4
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                1
  Open LV               0
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               15.99 GiB
  PE Size               4.00 MiB
  Total PE              4094
  Alloc PE / Size       3072 / 12.00 GiB
  Free  PE / Size       1022 / 3.99 GiB
  VG UUID               sb9f6E-tlhF-PqmE-F3Te-IqOa-RFH4-NcD3jQ

  --- Logical volume ---
  LV Path                /dev/FNK/LT
  LV Name                LT
  VG Name                FNK
  LV UUID                uQd7Z0-2xvU-RD9s-hOem-fPdE-YA1f-Gcd4xw
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2020-07-01 12:33:16 -0400
  LV Status              available
  # open                 0
  LV Size                12.00 GiB
  Current LE             3072
  Segments               2
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:0

  --- Physical volumes ---
  PV Name               /dev/sdb     
  PV UUID               NACDEl-ZZjS-IRaO-cOfC-SeSa-tjrw-oyWCJm
  PV Status             allocatable
  Total PE / Free PE    2047 / 0

  PV Name               /dev/sdc     
  PV UUID               iKQcoX-1sJA-xbQw-h0iw-3Ajm-zZI6-vcEIHA
  PV Status             allocatable
  Total PE / Free PE    2047 / 1022

    Archiving volume group "FNK" metadata (seqno 2).
    Archiving volume group "FNK" metadata (seqno 4).
    Creating volume group backup "/etc/lvm/backup/FNK" (seqno 4).
    Cache: Duplicate VG name FNK: Prefer existing sb9f6E-tlhF-PqmE-F3Te-IqOa-RFH4-NcD3jQ vs new 9BwcTY-5aSy-pz1j-2paY-jNBS-q79W-7199io
    （注意看这里）缓存：重复的VG名称FNK：优先使用现有的sb9f6E-tlhF-PqmE-F3Te-IqOa-RFH4-NcD3jQ与新的9BwcTY-5aSy-pz1j-2paY-jNBS-q79W-7199io
 --- Volume group ---
  VG Name               FNK
  System ID             
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  2
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                1
  Open LV               0
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               15.99 GiB
  PE Size               4.00 MiB
  Total PE              4094
  Alloc PE / Size       3072 / 12.00 GiB
  Free  PE / Size       1022 / 3.99 GiB
  VG UUID               9BwcTY-5aSy-pz1j-2paY-jNBS-q79W-7199io

  --- Logical volume ---
  LV Path                /dev/FNK/LT
  LV Name                LT
  VG Name                FNK
  LV UUID                RiQ9UN-Pu7s-fb3U-8uvg-XWfH-jF7R-vd2zC3
  LV Write Access        read/write
  LV Creation host, time localhost.localdomain, 2020-07-01 13:18:22 -0400
  LV Status              NOT available
  LV Size                12.00 GiB
  Current LE             3072
  Segments               2
  Allocation             inherit
  Read ahead sectors     auto

  --- Physical volumes ---
  PV Name               /dev/sdd     
  PV UUID               Wmf1Gp-0sdn-ta0m-35l3-95WV-11Lr-Z4swGm
  PV Status             allocatable
  Total PE / Free PE    2047 / 0

  PV Name               /dev/sde     
  PV UUID               6thfiv-mdiU-tCDz-j1K6-HkbZ-sHgE-jnKoTb
  PV Status             allocatable
  Total PE / Free PE    2047 / 1022

    Archiving volume group "FNK" metadata (seqno 4).
    Archiving volume group "FNK" metadata (seqno 2).
    Creating volume group backup "/etc/lvm/backup/FNK" (seqno 2).

vg组改名（注意是把已经激活的vg进行改名，因为未激活的改不了）

    vgrename xxxx-vgid-xxxx-xxxx xinname