P4300 Snaphot Backups via iSCSI

[David Strydom]

Hi there,

We have a cluster of 2 P4300 4TB iSCSI NAS devices. We have a variety of servers using the NAS, both linux and windows. What I am trying to figure out is how to backup data directly from a snapshot on the NAS.

We have a MS Server 2003 running Backup Exec 12 if that helps.

Any advise will be appreciated.

Thanks
David

[Uwe Zessin]

The P4300 is an iSCSI "SAN" (it serves disk blocks, not files). A snapshot looks like a "photocopy" of the filesystem on the iSCSI volume. You can make changes to the original, but they do not appear on the snapshot.

If you present the snapshot to the backup server, it can pick up the Windows NTFS filesystems, but it will not understand the Linux filesystem.

[David Strydom]

Thanks for your response, for the NTFS machines, do you know how I would get the backup server to mount the latest snapshot automatically so it can become part of the dialy backups.

[Uwe Zessin]

Windows has a framework for this called the Volume Shadow copy Service (VSS). One of the features is called a "transportable snapshot". I don't now if Backup Exec supports that mechanism. If not, it should be possible to work around this with the VSS SDK.

[David Strydom]

Thanks I will have a play with this. In the meantime does anyone know how I would do the same for linux.

Thanks
David

[peyrache]

for linux you can use a product called Storage Mirorring
JYP