Getting an error when mounting LVM snapshot
- by Sandra
I have migrated a file based Xen guest to LVM using
dd bs=1M if=/dev/zero of=/dev/vg00/vm10
qemu-img convert ~/vm10.qcow2 -O raw /dev/vg00/vm10
and changed the Xen domain file for the VM to use the LV instead of the old file.
The VM boots up, and now on the Xen host would I like to make a snapshot of the running VM.
# lvcreate --size 10G --snapshot --name vm10-snapshot /dev/vg00/vm10
Logical volume "vm10-snapshot" created
# mount /dev/vg00/vm10-snapshot /mnt/snapshot/
mount: you must specify the filesystem type
# dmesg |tail
EXT3 FS on dm-3, internal journal
EXT3-fs: mounted filesystem with ordered data mode.
hfs: unable to find HFS+ superblock
VFS: Can't find ext3 filesystem on dev dm-4.
hfs: unable to find HFS+ superblock
hfs: unable to find HFS+ superblock
VFS: Can't find ext3 filesystem on dev dm-2.
hfs: unable to find HFS+ superblock
hfs: unable to find HFS+ superblock
hfs: unable to find HFS+ superblock
For some reason it can't see it is an EXT3 filesystem. I have also tried to mount with -t ext3, but still didn't mount.
# lvdisplay
--- Logical volume ---
LV Name /dev/vg00/vm10
VG Name vg00
LV UUID I1y1vQ-Bac5-5jwW-melh-TY5h-l9NO-qaelKk
LV Write Access read/write
LV snapshot status source of
/dev/vg00/vm10-snapshot [active]
LV Status available
# open 2
LV Size 8.00 GB
Current LE 2048
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:2
--- Logical volume ---
LV Name /dev/vg00/vm10-snapshot
VG Name vg00
LV UUID GWsOx3-TPpr-GW64-uiMz-u1YN-QU4h-l0Kala
LV Write Access read/write
LV snapshot status active destination for /dev/vg00/vm10
LV Status available
# open 0
LV Size 8.00 GB
Current LE 2048
COW-table size 10.00 GB
COW-table LE 2560
Allocated to snapshot 0.00%
Snapshot chunk size 4.00 KB
Segments 1
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:4
#
What could the problem be?
