Advice on VCB

[moussar]

Hi, we are just setting up our ESX cluster and I can't grasp the picture about VCB, and hope someone can help me understand.

The setup is a SAN with 3 ESX servers, planned is a dedicated backup server whitch also will connect to the SAN,

CommVault Galaxy as the backup application. Two VM's that will be fileserver and Exchange whitch will use raw data luns,

the rest is vmdk. The most important as I see it, is to keep the backup dataflow inside the SAN as much as possible.

To achieve this I was thinking to a picture like this:

\- install VCB on the (Commserv, whitch is also the mediaserver) backup server, connected to a tape library via scsi.

The server has its HBA to the Fibre switch.

\- Install the Filesystem iData agent on this server?? (Not sure if this is needed)

\- Configure VCB to mount the vmdk's and configure a Commserv subclient for each VM.

(The VM will have a FS iData agent).

What I'm still not sure about, is if this will backup from inside the VM's and route the stream via

the SAN to the BU server. This also goes for the Exchange and Fileserver data luns.

If this would work, the VM datastore has to be seen by the Windows BU server. Is this possible

without the risk of breaking things.

We have VI3 Enterpise and so VCB is already bought. The only remaining costs are for the Commserv agents.

Hope people who already went trough the backup strategies could help me here.

How did you guys tackled this?

Thanks in advance,

moussar

[Duncan Epping]

Agents inside the VM will not route the data via the HBA. They will route it via the NIC cause they are not aware of the fact that they are virtual.

VCB is for dumping the complete vmdk to the VCB proxy and backing it up, or for mounting the vmdk to the proxy and backing up the files inside the vmdk with an agent. this agent is based on the proxy. the vcb traffic will be routed via the HBA.

one thing you should not forget is to disable automounting on the VCB server before you connect it to the san and present the luns. if you don't disable automount than your lun's will be toasted.

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[moussar]

Ok, so to backup files inside the VMDK I'll need the Proxy iDATA agent inside the VM. Will the restore be transparent. I mean, one can restore directly from within the client in the commcell? Wonder if VCB then will mount the VM for the restore process to write data back to the VMDK.

Thanks.

[NorbK]

While I haven't done backups of raw luns with VCB, we do use VCB with Commvault. The VCB proxy needs to have auto-enumeration of drive letters turned off. In our environment we have a stand alone VCB proxy server and do not have VCB installed on a media agent. The only Commvault agent needed for a simple backup of your entire VM is a Windows File Agent on your VCB proxy server. This will allow for a crash consistent backup of your entire VM (meaning it would restore like someone had cut the power to the VM). You can also tell VCB to do a file level backup where it presents the drive letters, subfolders and files under the directory on the VCB proxy that you have chosen (default I believe is c:\mnt). This allows the Windows File Agent on the VCB proxy to backup individual files and folders there, but full backups, not incrementals. Restore process for either full VM or file level backups are somewhat manual, but doable. Its a cheap, workable solution, but nothing fancy. Also, if I remember correctly, I threw Commvaults recommendations out the window for the VCB scripts and created my own based on VMware docs for VCB.

[Duncan Epping]

VCB will not mount the vm for a restore. VCB is just a solution for backing up, not restoring.... the VMFS is mounted as read only. And to restore the full-vm you can use VMware Converter. Works like a charm, but still copies over the network and not the HBA.

[NorbK]

Yes it was nice of them to include support on convertor for restores. Much better than restoring to the proxy and then ftp'ing to the ESX server and then running a command to restore it!

[SteveMol]

I have just tried a restore using the converter. When I point it to the backed up files I get an, "Unable to determine Guest Operationg Sytem" error. ??

[SteveMol]

Seems VM Converter 3.01 fixes this error. I was running 3.0.0

[AustinPowers]

You can also use the VMware-mount utility to mount a backed up vmdk as a drive letter on the VCB proxy. Its excellent for restoring a single file or folder. I never got it working in the GUI, but its flawless at cmd prompt.

[moussar]

Thank you all for the info supplied.

It helped me understand the possibilities of VCB.

I think we'll go for the vm backup and leave filelevel backups up to commvault.

Regards.

[ax_s]

First of all the backup of a VM must be handled like a physical server. The VCB proxy gives you the possibility to make an image backup of the VM like i.e. a ghost image of a physical server.

The file based backup with VCB cannot be an alternative for a "real" backup software!

When using raw data luns, consider that there are two modes to attach them to a VM: physical and virtual.

If you use the physical mode, it is not possible to take a snapshot of that VM and for this you can't use VCB.

If you use virtual mode, the LUN is handled like a vmdk and functions of the SAN storage (i.e. extend the LUN) are not available for the vmdk.

VCB proxy can only mount the vmdks in read only mode, so it is not possible to make a file based restore with VCB. To do this, you can mount the vmdk with the vmware-mount utility and restore files with copying them over the network.

Axel