Ceph (RBD) group snapshot support

[hydro-b]

Description
Group snapshots in Ceph gives you the possibility to create a consistent snapshot of multiple (RBD) DISK IMAGES in the group at the same time.

Use case
VMs that act as for example as database server with several separate DISK IMAGES (separate data / log / wal) can be snapshotted consistently.

Interface Changes
Changes needed in CLI / Sunstone to provide a way to create a disk "group" and a separate command option / button resp. to create a group disk snapshot. Changes also in the drivers to provide support for group create, group image add, group image list, group image remove, group rename, group rm, group snap create, group snap rm, group snap rename.

Additional Context
AFAIK there is no support for this (yet) in libvirt ...

Progress Status

• Branch created
• Code committed to development branch
• Testing - QA
• Documentation
• Release notes - resolved issues, compatibility, known issues
• Code committed to upstream release/hotfix branches
• Documentation committed to upstream release/hotfix branches

[atodorov-storpool]

+1

This feature request sounds very reasonable!

For similar functionality currently I am re-purposing the VM Snapshot interface (which is useless for raw devices) with reconfiguration of the KVM's VMM_MAD to execute a custom set of scripts on the front-end instead of the default ones on the hosts.

Works like charm even the disk resize is not affected like the disk snapshots...
The customers are using the interface for rolling weekly/daily backups.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions. The OpenNebula Dev Team

[christian7007]

Related with #5523