Solved

HyperScale X and VSA backups using SAN transport mode

  • 1 February 2023
  • 3 replies
  • 411 views

Userlevel 2
Badge +11

Hello all,

 

I'd like to understand the steps taken by Commvault when a VSA backup from a vSphere environment uses a HSX block as access nodes/proxy. 

 

Consider that vSphere datastores are FC SAN based LUNs. So, best performance would be to use SAN transport mode on the cvlt side.

 

During the backup operation, how the datastore LUNs are presented to the appliance? I saw in the docs the following:

 

"For Linux proxies, you might need to rescan the SCSI or iSCSI bus after attaching devices.

For MediaAgents on the HyperScale 1.5 Appliance or HyperScale X Appliance, you can use the rescan-scsi-bus.sh script to force a rescan."

 

So, that rescan procedure, when it is required? Everytime a new datastore is presented to the virtual environment? If there's no new datastore, it is done only once during HSX deployment?

 

Regards,

Pedro

icon

Best answer by MichaelCapon 1 February 2023, 15:49

View original

3 replies

Userlevel 7
Badge +17

Hi @PedroRocha 

From OS and CV perspective a script to initiate a rescan should work fine, but I would not perform this on a high interval. Once a day should be fine during hours where you have low backup/restore activity preferably.
You might want to communicate this with support as adjustments to the appliance are not allowed and can cause issues, but a Re-scan is such a low impact acitivity, I can’t imagine this would be an issue.
 

Userlevel 2
Badge +11

Hi @PedroRocha,

 

If we’re performing a regular streaming backup and leveraging SAN Transport, The Hyperscale (1.5 / X ) Node(s) would need the SAN Datastore LUN’s presented to them for access.

For the Linux OS to see the VMFS Volumes of the attached LUN’s you would need to rescan the i/SCSI bus after they have been attached. - If this is being done at deployment then yes it would be a one-time operation.

If a new LUN is provisioned and attached in the future, it’s most likely you’d need to rescan again then.

 

Hope that helps. - Let me know if you need any more info.

 

Best Regards,

Michael

 

 

Hello Michael!

 

Thanks for the answer.

I saw in another thread that some people have configured the scsi but rescan script in CRON to have it automatically run from time to time. Is this a supported configuration by Commvault? Would this interfere with support?

Regards,

Pedro Rocha.

Userlevel 6
Badge +14

Hi @PedroRocha,

 

If we’re performing a regular streaming backup and leveraging SAN Transport, The Hyperscale (1.5 / X ) Node(s) would need the SAN Datastore LUN’s presented to them for access.

For the Linux OS to see the VMFS Volumes of the attached LUN’s you would need to rescan the i/SCSI bus after they have been attached. - If this is being done at deployment then yes it would be a one-time operation.

If a new LUN is provisioned and attached in the future, it’s most likely you’d need to rescan again then.

 

Hope that helps. - Let me know if you need any more info.

 

Best Regards,

Michael

 

 

Reply