Backup datastore and disk signatures

[JeroenBuren]

Hi,

I have 4 datastores that I try to backup with BackupExec 2010. For this to work across the SAN I had to assign the datastores to the backup server. But I can only make backups of 2 datastores that are "seen" by Windows.The other 2 are unknown and don't have a disk signature.

My question is: "how is it possible that 2 out of 4 datastores have a Windows disk signature". And how can I make them available in Windows without disrupting VMware?

When I write the disk signature, do I loose all content of the disk?

I hope someone can help me with this...

[FranckRookie]

Hi Jeroen,

Welcome to the forum.

When you write "datastores that are seen by Windows", do you mean that you mount the VMFS file system on you Windows then ask BackupExec to back it up? Does not sound to be a good idea. Windows is not able to understand the VMFS files system and you could mess all your datastore up.

If BackupExec is able to understand the VMFS file system, then present the LUNs to the Windows machine but do not mount them. Let BackupExec access the LUNs and move the data to the backup space. Otherwise, use VCB to export data from VMFS to a temporary storage and then BackupExec on that exported data.

Good luck.

Regards

Franck

[JeroenBuren]

Hi Franck,

I know that Windows could mess up a VMFS disk. But in order to create a SAN-based backup through a VMware agent I need to assign the VMware LUNs to the backup server. But when I look at the Disk Administrator of the backup server I see something that I didn't expect. Two out of four LUNs are "recognised" by Windows! That doesn't make sense. But on the other hand, I can only backup VMs that have their files on a "recognised" LUN... Backing up other VMs throws an error that I don't have access to the disk... I have included an image of the Disk Administrator tool.

[FranckRookie]

OK, so BackupExec should be able to access VMFS using vStorage API.

I found a few threads about BackupExec vSphere SAN mode backup. You should normally have all your volumes showing as "unknown volumes" in disk manager... Strange! Is your media server installed on Windows 2003 or 2008? Is there any difference between the LUNs on the SAN side? Do you remember how two of your LUNs got signed?

Apparently it doesn't mess all up as your ESXs are still accessing the LUNs. The place where Windows writes its disk signature should not be used by VMware.

I would suggest creating a new small LUN a make the test to present it to the ESXs and your media server. Then try to sign it and see what happens...

Good luck.

Regards

Franck

[JeroenBuren]

The backup server is Windows Server 2008. On the SAN side all four LUNs are the same. The only difference is the size... But I have absolutely no idea how two LUNs got signed. I will move the VMs to another datastore and see what happens when I do sign the LUN. I will post results. And eventually I need to sign the remaining LUNs because I need to access them in order to create a backup.

[JeroenBuren]

Didn't have the time to do it earlier but when I tried to write the signature I got an error telling me the disk was write protected. So unable to write a signature... Now I'm stuck! Who should I turn to? Symantec because BackupExec cannot access the disk? Or is it a problem with software from VMWare? Or do I need to contact the disk vendor (HP)?

[FranckRookie]

Asking Symantec should be more efficient. Forget about HP, the problem is not related to the disk itself.