Data Recovery


With Ceph's RBD snapshots, we are able to restore RBD images to previous states in order to recover data.

Ceph RBD

On a Ceph admin node, (substitute <IMAGE NAME> with the appropriate image path e.g. virtual-machines/steeltoe)
  1. 1.
    find the appropriate image by running rbd ls
  2. 2.
    list all the image's snapshots by running rbd snap ls <IMAGE NAME> and gain information about the image with rbd info <IMAGE NAME> .
  3. 3.
    disable necessary features with rbd feature disable <IMAGE NAME> object-map fast-diff
  4. 4.
    enable layering for RBD copy-on-write ( with rbd feature enable <IMAGE NAME> layering
  5. 5.
    using the image snapshot name obtained in step 2
For example to restore an image named virtual-machines/steeltoe from the snapshot 20190108 :
rbd feature disable virtual-machines/steeltoe object-map fast-diff
cd /mnt
mkdir steeltoe
rbd map virtual-machines/[email protected]
mount /dev/rbd/virtual-machines/[email protected] /mnt/steeltoe
# Obtain the necessary files from /mnt/steeltoe
umount /mnt/steeltoe
rbd unmap virtual-machines/steeltoe
rbd feature enable virtual-machines/steeltoe object-map fast-diff