Question

VM Group access node affinity

  • 26 October 2023
  • 3 replies
  • 45 views

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Is there any way to specify within a VM Group an affinity for certain access nodes for certain backup types? I am using Auto transport mode because most of my VM’s can utilize my Windows MediaAgent VM’s for HotAdd, however a few of them need to fall back on NBD. When they do NBD via our HSX nodes, they get great throughput and the jobs finish quickly. However, they are often selecting the Windows MediaAgent VM’s for NBD and the throughput is abysmal, causing the jobs to take 5-7 hours longer than they should to complete.

Is there any way to control this within the VM Group? If not, has CommVault ever considered adding access node affinity/anti-affinity as a feature? Or perhaps modify the access node selection logic to reference the throughput/runtime of past jobs and realize that selecting incredibly slow access nodes for NBD is not a good idea?


3 replies

Userlevel 6
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@Zer0c00L ,

Can you review this:

https://documentation.commvault.com/2022e/expert/32272_vm_dispatch_and_proxy_selection_for_vmware_backups.html

Let me know:

Best Regards,

Sebastien

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This is helpful documentation. Where it says:

“You can create different proxies for different backup methods (for example, different proxies for HotAdd, SAN, or NBD) and associate those proxies with the appropriate subclients.”

How do I accomplish this? Are they just saying use separate VM groups for HotAdd, NBD clients etc.?

Edit: I found this article: https://documentation.commvault.com/2022e/expert/31115_performance_tuning_for_backups.html

But I’m not really seeing a setting that would accomplish what I’m trying to do (Designate my HSX nodes for NBD transport, and my Windows MediaAgents for HotAdd).

Edit 2: Found this repository of “Additional Settings” and searched for HotAdd: https://documentation.commvault.com/additionalsetting/search.html?q=hotadd

Which brought me to this: https://documentation.commvault.com/additionalsetting/details?name=%22vStorageTransportMode%22&id=979

This might be the ticket. So if I apply this Additional Setting to my Windows MediaAgents I want to use ONLY for HotAdd, I would apply this setting “vStorageTransportMode” with value “hotadd” ?

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I tested out this additional setting. It seems that after making this change on my Windows HotAdd MediaAgents, HSX nodes are no longer being selected from the access node pool for NBD at all anymore. It caused a few VM’s to fail with “failed to open disk” errors. How can I get these VM’s to select NBD? I thought they would automatically select NBD via HSX if HotAdd failed.

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