Please refer to the steps below on how to Mount Snapshot created with DiskSafe in CentOS7
List all the availble snapshot and record down the timestamp ID
[root@centos7 ~]# dscli snapshot list sda
All snapshots of sda
Snapshot 1:
Snapshot Timestamp = 1535448502(2018/08/28 17:28:22)
Snapshot Blocks Count = 6299648
Mounted = NO
Snapshot 2:
Snapshot Timestamp = 1535450090(2018/08/28 17:54:50)
Snapshot Blocks Count = 386924544
Mounted = NO
Snapshot 3:
Snapshot Timestamp = lsblk(2018/08/28 18:54:56)
Snapshot Blocks Count = 65536
Mounted = NO
Snapshot count : 3
Mount the snapshot and record down the snapshot device name /dev/sde
[root@centos7 ~]# dscli snapshot mount sda timestamp=1535453696
Mount snapshot with timestamp 1535453696 of sda
Snapshot mounted, get the information...
Snapshot device name: /dev/sde
Command succeeded
add “a|^/dev/sde2$|” in global_filter in /etc/lvm/lvm.conf to allow vgscan to discover the newly added /dev/sde device
vi /etc/lvm/lvm.conf
# Accept every block device:
global_filter = [ "a|^/dev/disksafe/sda$|", "a|^/dev/disksafe/sda2$|", "a|^/dev/sde2$|", "r|.*|" ]
We manage to see the snapshot now, but we need to resolve the deplicate PVs issue – PV GYQLfY-9Is6-SNqD-gvAx-PyTB-ihv9-w5X95l on /dev/sde2 was already found on /dev/disksafe/sda2 to allow it to be mounted in later stage
[root@centos7 lvm]# pvdisplay
WARNING: PV GYQLfY-9Is6-SNqD-gvAx-PyTB-ihv9-w5X95l on /dev/sde2 was already found on /dev/disksafe/sda2.
WARNING: Disabling lvmetad cache which does not support duplicate 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: PV GYQLfY-9Is6-SNqD-gvAx-PyTB-ihv9-w5X95l on /dev/sde2 was already found on /dev/disksafe/sda2.
WARNING: PV GYQLfY-9Is6-SNqD-gvAx-PyTB-ihv9-w5X95l prefers device /dev/disksafe/sda2 because device is used by LV.
--- Physical volume ---
PV Name /dev/disksafe/sda2
VG Name centos
PV Size <9.00 GiB / not usable 3.00 MiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 2303
Free PE 0
Allocated PE 2303
PV UUID GYQLfY-9Is6-SNqD-gvAx-PyTB-ihv9-w5X95l
Resolved the Duplicate PV issue and a new VG – centos11 is show in /dev/sde2 (PV) now
[root@centos7 lvm]# vgimportclone /dev/sde2
WARNING: PV GYQLfY-9Is6-SNqD-gvAx-PyTB-ihv9-w5X95l on /dev/sde2 was already found on /dev/disksafe/sda2.
WARNING: PV GYQLfY-9Is6-SNqD-gvAx-PyTB-ihv9-w5X95l prefers device /dev/disksafe/sda2 because device is used by LV.
[root@centos7 lvm]# vgimportclone /dev/sde2
[root@centos7 lvm]# pvdisplay
--- Physical volume ---
PV Name /dev/sde2
VG Name centos11
PV Size <9.00 GiB / not usable 3.00 MiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 2303
Free PE 0
Allocated PE 2303
PV UUID Om09CY-VONn-pTZY-erVN-XqrL-wVlr-ITfb3T
--- Physical volume ---
PV Name /dev/disksafe/sda2
VG Name centos
PV Size <9.00 GiB / not usable 3.00 MiB
Allocatable yes (but full)
PE Size 4.00 MiB
Total PE 2303
Free PE 0
Allocated PE 2303
PV UUID GYQLfY-9Is6-SNqD-gvAx-PyTB-ihv9-w5X95l
Rescan the VG & LV
[root@centos7 lvm]# vgscan
Reading volume groups from cache.
Found volume group "centos11" using metadata type lvm2
Found volume group "centos" using metadata type lvm2
[root@centos7 lvm]# lvscan
inactive '/dev/centos11/swap' [1.00 GiB] inherit
inactive '/dev/centos11/root' [<8.00 GiB] inherit
ACTIVE '/dev/centos/swap' [1.00 GiB] inherit
ACTIVE '/dev/centos/root' [<8.00 GiB] inherit
Activate the LV that we would like to mount manually
[root@centos7 lvm]# lvchange -ay /dev/centos11/root
[root@centos7 lvm]# lvscan
inactive '/dev/centos11/swap' [1.00 GiB] inherit
ACTIVE '/dev/centos11/root' [<8.00 GiB] inherit
ACTIVE '/dev/centos/swap' [1.00 GiB] inherit
ACTIVE '/dev/centos/root' [<8.00 GiB] inherit
If you try to mount the new LV – /dev/centos11/root, you will get the duplicate UUID error as below
[root@centos7 lvm]# mount /dev/centos11/root /mnt
mount: wrong fs type, bad option, bad superblock on /dev/mapper/centos11-root,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so.
[root@centos7]dmesg
[10811.766108] XFS (dm-4): Filesystem has duplicate UUID 0623d025-0721-419a-8ce2-e8e9adc318d3
Mount the volume without UUID specified
[root@centos7 /]# mount -o nouuid /dev/centos11/root /mnt
[root@centos7 /]# ls /mnt
bin dev etc jcameron-key.asc lib64 mnt proc run srv tmp var
boot disksafe home lib media opt root sbin sys usr
The snapshot is mounted successfully now, and you can look for the files you want for recovery purpose
Once you done for recovery, and you can release the snapshot mounted
[root@centos7 /]# umount /mnt
[root@centos7 /]# dscli snapshot unmount sda timestamp=1535453696
Dismount snapshot with timestamp 1535453696 of sda
Command succeeded
[root@centos7 /]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 10G 0 disk
├─sda1 8:1 0 1G 0 part
└─sda2 8:2 0 9G 0 part
sdb 8:16 0 20G 0 disk
├─sdb1 8:17 0 1G 0 part
└─sdb2 8:18 0 9G 0 part
sr0 11:0 1 1024M 0 rom
disksafe!sda 188:0 0 10G 0 disk
├─disksafe!sda1 188:1 0 1G 0 part /boot
└─disksafe!sda2 188:2 0 9G 0 part
├─centos-swap 253:0 0 1G 0 lvm [SWAP]
└─centos-root 253:1 0 8G 0 lvm /
Mouted Snapshot had been released successfully