topic Re: cache/capacity disks need to be in same ESXI-host? in VMware vSAN Discussions

cache/capacity disks need to be in same ESXI-host?

jerry5 — Mon, 08 Nov 2021 20:51:16 GMT

I am new to vSan concept and practice.

I got a question on vSan concept:

Currently, I assign one disk as cache-disk in one ESXI host.
I assign one disk as capacity-disk in another ESXI host.
And I can not proceed as there are "Claiming issues"
do cache/capacity disks need to be in the same ESXI host?

Thanks!

(For reference, I attached two screenshots)

Re: cache/capacity disks need to be in same ESXI-host?

CyberNils — Tue, 09 Nov 2021 08:28:11 GMT

Yes, you need at least one cache disk and one capacity disk per host.

Re: cache/capacity disks need to be in same ESXI-host?

TheBobkin — Tue, 09 Nov 2021 08:28:49 GMT

@jerry5 Yes - Disk-Groups are comprised of 1 Cache-tier SSD/NVMe and 1-7 Capacity-tier HDD/SSD/NVMe on each node, these are local-only (e.g. physically in a single ESXi host).

Re: cache/capacity disks need to be in same ESXI-host?

TheBobkin — Tue, 09 Nov 2021 08:46:14 GMT

@CyberNils , Actually it is not mandatory for a vSAN node to have Disk-Groups - you can have compute-only nodes. If you meant you need minimum 1 Cache-tier device + Capacity-tier device per node to make a Disk-Group, that would be true.

Re: cache/capacity disks need to be in same ESXI-host?

jerry5 — Tue, 09 Nov 2021 16:19:46 GMT

Thank Nils, Bobkin: you guys save my time and energy!

Re: cache/capacity disks need to be in same ESXI-host?

CyberNils — Wed, 10 Nov 2021 08:01:59 GMT

I know, but it was pretty obvious that this guy was not trying to add a compute only node to an existing cluster...