Santi Saez wrote:

Hi,

I want to take snapshots of a iSCSI devices from a target that hasn't snapshot/cloning capabilities (it's a Infortrend A16E storage array).

What method are you using to make snapshots/clones of iSCSI targets using Open-iSCSI + CentOS? What about using Open-iSCSI + LVM snapshots system? For example:

• Take a LVM snapshot in the initiator with "lvcreate".
• Give read-only access to the backup server, for the same LUN/volume.
• In the backup server, mount in read-only mode this snapshot.
• Take a backup of this snapshot, using dd/tar/rsync for example.
• Unmount the snapshot in the backup server.
• Remove this snapshot from the host with "lvremove".

Is there any soft to make this? thanks! NOTE: It's a must, that device snapshots must be in other device.. not in the same target.

as I understand it, LVM snapshots are copy-on-write. that means the data blocks of the LVM snapshot are quite dynamic when the underlying original volume is changing. I do NOT think it would be even remotely safe to mount this read only on another environment as that OS wouldn't have a clue the underlying LVM stuff was being changed while its reading it.