Mount Ceph Snapshots for file level backup

[st6f9n]

Hello,

is there an understandable documentation how to mount ceph snapshots for file level backup
(I' m using rsnapshot) ? This one is a bit confusing for me:
https://forum.proxmox.com/threads/is-it-possible-to-mount-ceph-snapshot-for-backup-with-borg.59492/

Thanks

Stefan

 

[fiona]

Hi,
the commands in the thread you linked to are not specific to 'Borgbackup'. In this post you have the all the commands you'll need. If it's a VM and not a container you'll need to specify the partition as well, e.g.

mount -o noload /dev/rbd/rbd-kvm/vm-103-disk-0@snap-part1 /path/to/mountpoint/

Once mounted, you can use your favorite file-level backup tool. And after doing the backup you can do the rest of those commands to unmount and destroy the snapshot again.

 

[st6f9n]

Thank you for your help !
Stefan

 

[st6f9n]

Hello,

now it nearly works, but I get "already mounted or mount point busy". I cannot find any reasons.

rbd ls pool2-1 :
vm-100-disk-0
vm-101-disk-1

rbd --pool pool2-1 snap create pool2-1/vm-101-disk-1@test

rbd --pool pool2-1 snap ls vm-101-disk-1 :
SNAPID NAME SIZE PROTECTED TIMESTAMP
28 test 20 GiB Tue Dec 10 16:20:40 2019

rbd map --read-only pool2-1/vm-101-disk-1@test :
/dev/rbd0

rbd showmapped :
id pool namespace image snap device
0 pool2-1 vm-101-disk-1 test /dev/rbd0

mkdir -p /mnt/tmp

kpartx -va /dev/rbd/pool2-1/vm-101-disk-1@test :
add map vm-101-disk-1@test1 (253:3): 0 8388608 linear 252:0 2048
add map vm-101-disk-1@test2 (253:4): 0 33552384 linear 252:0 8390656

mount -o noload /dev/rbd/pool2-1/vm-101-disk-1@test-part2 /mnt/tmp :
mount: /mnt/tmp: /dev/rbd0p2 already mounted or mount point busy.

lsof /dev/rbd0p2 : <nothing>
lsof /dev/rbd/pool2-1/vm-101-disk-1@test-part2 : <nothing>

kpartx -vd /dev/rbd/pool2-1/vm-101-disk-1@test :
del devmap : vm-101-disk-1@test2
del devmap : vm-101-disk-1@test1

rbd unmap /dev/rbd/pool2-1/vm-101-disk-1@test

sync

rbd --pool pool2-1 snap ls vm-101-disk-1 :
SNAPID NAME SIZE PROTECTED TIMESTAMP
28 test 20 GiB Tue Dec 10 16:20:40 2019

rbd snap rm pool2-1/vm-101-disk-1@test :
Removing snap: 100% complete...done.

 

[fiona]

The problem is probably the kpartx commands. Please try again without those.

 

[st6f9n]

Did not help.

Stefan

 

[st6f9n]

Sorry, my failure. kpartx is the reason. Now it works

Stefan