Ceph » rbd

#Steps

root@server1:/workspace/ceph/build# rbd-a create -s 12M data/test
root@server1:/workspace/ceph/build# rbd-a mirror image enable data/test snapshot
Mirroring enabled
root@server1:/workspace/ceph/build# rbd-a info data/test
rbd image 'test':
    size 12 MiB in 3 objects
    order 22 (4 MiB objects)
    snapshot_count: 1
    id: 10359ed195d5
    block_name_prefix: rbd_data.10359ed195d5
    format: 2
    features: layering, exclusive-lock, object-map, fast-diff, deep-flatten
    op_features: 
    flags: 
    create_timestamp: Wed Apr 16 16:47:52 2025
    access_timestamp: Wed Apr 16 16:47:52 2025
    modify_timestamp: Wed Apr 16 16:47:52 2025
    mirroring state: enabled
    mirroring mode: snapshot
    mirroring global id: 79e8ea6d-a79b-403a-9084-dc63b72eac20
    mirroring primary: true
root@server1:/workspace/ceph/build# rbd-b info data/test
rbd image 'test':
    size 12 MiB in 3 objects
    order 22 (4 MiB objects)
    snapshot_count: 1
    id: 103545ce601
    block_name_prefix: rbd_data.103545ce601
    format: 2
    features: layering, exclusive-lock, object-map, fast-diff, deep-flatten, non-primary
    op_features: 
    flags: 
    create_timestamp: Wed Apr 16 16:48:03 2025
    access_timestamp: Wed Apr 16 16:48:03 2025
    modify_timestamp: Wed Apr 16 16:48:03 2025
    mirroring state: enabled
    mirroring mode: snapshot
    mirroring global id: 79e8ea6d-a79b-403a-9084-dc63b72eac20
    mirroring primary: false

## Kill the rbd-mirror daemon on the secondary

root@server1:/workspace/ceph/build# ps ax |grep rbd
1225550 ?        Ssl    0:00 bin/rbd-mirror --cluster site-a
1225578 ?        Ssl    0:00 bin/rbd-mirror --cluster site-b
1226030 pts/1    S+     0:00 grep --color=auto rbd
root@server1:/workspace/ceph/build# kill -9 1225578
root@server1:/workspace/ceph/build# ps ax |grep rbd
1225550 ?        Ssl    0:00 bin/rbd-mirror --cluster site-a
1226032 pts/1    S+     0:00 grep --color=auto rbd

## Demote the primary image. The demote snap will not be synced to the secondary as the rbd-mirror daemon is not running
root@server1:/workspace/ceph/build# rbd-a mirror image demote data/test
2025-04-16T16:48:50.610+0530 7f0ff1a006c0 -1 librbd::Operations: update notification timed-out
Image demoted to non-primary

root@server1:/workspace/ceph/build# rbd-a info data/test
rbd image 'test':
    size 12 MiB in 3 objects
    order 22 (4 MiB objects)
    snapshot_count: 2
    id: 10359ed195d5
    block_name_prefix: rbd_data.10359ed195d5
    format: 2
    features: layering, exclusive-lock, object-map, fast-diff, deep-flatten, non-primary
    op_features: 
    flags: 
    create_timestamp: Wed Apr 16 16:47:52 2025
    access_timestamp: Wed Apr 16 16:47:52 2025
    modify_timestamp: Wed Apr 16 16:47:52 2025
    mirroring state: enabled
    mirroring mode: snapshot
    mirroring global id: 79e8ea6d-a79b-403a-9084-dc63b72eac20
    mirroring primary: false

root@server1:/workspace/ceph/build# rbd-a snap ls --all data/test
SNAPID  NAME                                                                                       SIZE    PROTECTED  TIMESTAMP                 NAMESPACE                                                         
     3  .mirror.primary.79e8ea6d-a79b-403a-9084-dc63b72eac20.b0c1e273-b2db-4213-9e3a-76c89c5fc234  12 MiB             Wed Apr 16 16:48:01 2025  mirror (primary peer_uuids:[0188fbc9-6104-40b6-a108-96ad19cbd53e])
     4  .mirror.primary.79e8ea6d-a79b-403a-9084-dc63b72eac20.8f440332-4ce9-4807-84cc-4209e5a73501  12 MiB             Wed Apr 16 16:48:45 2025  mirror (demoted peer_uuids:[0188fbc9-6104-40b6-a108-96ad19cbd53e])

root@server1:/workspace/ceph/build# rbd-b snap ls --all data/test
SNAPID  NAME                                                                                           SIZE    PROTECTED  TIMESTAMP                 NAMESPACE                                                                       
     3  .mirror.non_primary.79e8ea6d-a79b-403a-9084-dc63b72eac20.02c1392b-af78-4446-9e36-dfa74b4dbd39  12 MiB             Wed Apr 16 16:48:03 2025  mirror (non-primary peer_uuids:[] d4594fcb-4641-47b2-a0d7-279c82aa2f9e:3 copied)

## Trigger a resync on the secondary
root@server1:/workspace/ceph/build# rbd-b mirror image resync data/test
Flagged image for resync from primary

## Start the rbd-mirror daemon on the secondary
root@server1:/workspace/ceph/build# bin/rbd-mirror --cluster site-b
root@server1:/workspace/ceph/build# rbd-b info data/test
rbd: error opening image test: (2) No such file or directory