CentOS - Dec 2008 - Best way to take snapshots of iSCSI devices using Open-iSCSI + CentOS

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.

Regards,

--
Santi Saez
http://woop.es

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.

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).
Go get the snapshot software for the array?

http://www.infortrend.com/main/2_product/sw_snapshot.asp

Seems new, last time I checked out infortrend they didn't have
snapshot software.

nate