Linux 硬盤UUID相同處理方法

OVF模板部署的linux虛擬機磁盤id是相同的，當同一個模板生成的虛擬機掛載虛擬機磁盤時就會遇到兩個磁盤UUID相同的狀況，致使系統啓動後只能識別一個磁盤。這裏介紹一下LVM分區的磁盤UUID相同的處理方法
（對於非lvm就更簡單，直接參考《3、處理分區信息》修改uuid便可。）

1、查看磁盤信息
1.1 查看全部分區及uuid信息
（vg的名稱爲centos，有兩個lv，分別是root和swap）
[root@centos7 ~]# lsblk -f
NAME FSTYPE LABEL UUID MOUNTPOINT
sda
├─sda1 xfs 85082005-65c6-476a-a996-0063d6c395fd
└─sda2 LVM2_member qtCH1O-JNWW-svVN-CF61-OOn7-LxvA-SyOlfs
├─centos-root xfs faf28794-0fba-4753-becf-d47f003630d1 /
└─centos-swap swap e5ca3ca9-0404-4887-b0bd-5a6ab4a6cf64 [SWAP]
sdb
├─sdb1 xfs 85082005-65c6-476a-a996-0063d6c395fd /boot
└─sdb2 LVM2_member qtCH1O-JNWW-svVN-CF61-OOn7-LxvA-SyOlfs
sr0

1.2 查看pv、vg、lv均提示「duplicate PVs were found」
[root@centos7 ~]# pvs
WARNING: Not using lvmetad because duplicate PVs were found.
WARNING: Use multipath or vgimportclone to resolve duplicate PVs?
WARNING: After duplicates are resolved, run "pvscan --cache" to enable lvmetad.
WARNING: Not using device /dev/sdb2 for PV qtCH1O-JNWW-svVN-CF61-OOn7-LxvA-SyOlfs.
WARNING: PV qtCH1O-JNWW-svVN-CF61-OOn7-LxvA-SyOlfs prefers device /dev/sda2 because device is used by LV.
PV VG Fmt Attr PSize PFree
/dev/sda2 centos lvm2 a-- <39.00g 4.00m

2、激活vg
2.1 由於這兩塊磁盤（非多路徑磁盤），因此使用vgimportclone處理
[root@centos7 ~]# vgimportclone -n newcentos /dev/sdb2
WARNING: Not using device /dev/sdb2 for PV qtCH1O-JNWW-svVN-CF61-OOn7-LxvA-SyOlfs.
WARNING: PV qtCH1O-JNWW-svVN-CF61-OOn7-LxvA-SyOlfs prefers device /dev/sda2 because device is used by LV.

2.2 啓用pv
[root@centos7 ~]# pvscan --cache
[root@centos7 ~]# pvs
PV VG Fmt Attr PSize PFree
/dev/sda2 centos lvm2 a-- <39.00g 4.00m
/dev/sdb2 newcentos lvm2 a-- <39.00g 4.00m
[root@centos7 ~]# vgs
VG #PV #LV #SN Attr VSize VFree
centos 1 2 0 wz--n- <39.00g 4.00m
newcentos 1 2 0 wz--n- <39.00g 4.00m

# 此時「newcentos」的兩個lv狀態爲非active
[root@centos7 ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
root centos -wi-ao---- <35.00g
swap centos -wi-ao---- <4.00g
root newcentos -wi------- <35.00g
swap newcentos -wi------- <4.00g
[root@centos7 ~]#

2.3 啓用vg
# active newcentos（a：active 、y：yes、n：no）
[root@centos7 ~]# vgchange newcentos -ay
2 logical volume(s) in volume group "newcentos" now active

# 此時lv已經active
[root@centos7 ~]# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert
root centos -wi-ao---- <35.00g
swap centos -wi-ao---- <4.00g
root newcentos -wi-a----- <35.00g
swap newcentos -wi-a----- <4.00g

3、處理分區信息
3.1 雖然vg顯示已經正常了，可是掛載lv時依舊失敗，日誌提示的內容是uuid相同
[root@centos7 ~]# mount /dev/mapper/newcentos-root /mnt/
mount: wrong fs type, bad option, bad superblock on /dev/mapper/newcentos-root,
missing codepage or helper program, or other error
[root@centos7 ~]# dmesg |tail
[ 854.482564] XFS (dm-3): Filesystem has duplicate UUID faf28794-0fba-4753-becf-d47f003630d1 - can't mount

3.2 經過blkid或者lvdisplay查看uuid會發現「/dev/mapper/centos-root」和「newcentos-root」是同樣的
[root@centos7 ~]# blkid
/dev/sda1: UUID="85082005-65c6-476a-a996-0063d6c395fd" TYPE="xfs"
/dev/sda2: UUID="qtCH1O-JNWW-svVN-CF61-OOn7-LxvA-SyOlfs" TYPE="LVM2_member"
/dev/sdb1: UUID="85082005-65c6-476a-a996-0063d6c395fd" TYPE="xfs"
/dev/sdb2: UUID="y09RBQ-B06M-8cOP-PR2I-X7k0-4OOw-gbl24f" TYPE="LVM2_member"
/dev/mapper/centos-root: UUID="faf28794-0fba-4753-becf-d47f003630d1" TYPE="xfs"
/dev/mapper/centos-swap: UUID="e5ca3ca9-0404-4887-b0bd-5a6ab4a6cf64" TYPE="swap"
/dev/mapper/newcentos-swap: UUID="e5ca3ca9-0404-4887-b0bd-5a6ab4a6cf64" TYPE="swap"
/dev/mapper/newcentos-root: UUID="faf28794-0fba-4753-becf-d47f003630d1" TYPE="xfs"

3.3 有兩種方式處理
3.3.1 mount禁用uuid
mount -o nouuid /dev/mapper/newcentos-root /mnt

3.3.2 修改uuid
（xfs文件系統）
xfs_admin -U generate /dev/mapper/newcentos-root
Clearing log and setting UUID
writing all SBs

（ext二、三、4文件系統）
tune2fs /dev/sdc1 -U time
tune2fs 1.42.9 (28-Dec-2013)
clear clear the filesystem UUID
random generate a new randomly-generated UUID
time generate a new time-based UUID

# 再次掛載分區[root@centos7 ~]# mount /dev/mapper/newcentos-root /mnt