CAU and CVM based Cluster

BenM · Mon Oct 20, 2025 8:31 am

Hi Guys,

Just got around to looking at making CAU work again after updating the cluster and Starwind to use the CVM rather than a local host install. Yes - its been a while and yes the cluster servers have been being updated but by hand rather than automatically.

I was wondering about the pause/resume type thing that the Starwind CAU scripts did for the local host install and if something similar was required for the CVM based cluster? Or do we expect that Hyper-V manages the shutdown/resume of the CVM roles sufficiently well to avoid the need for a pause/resume script?

Mon Oct 20, 2025 12:21 pm

Hi,

The script was not tested with CVM but it can theoretically work with CVM as all the script does is checking StarWind VSAN part. You can target it to CVM IPs and that should do the trick.
The problem is that the CVM might suffer from adapter mix-up in the latest build, leading to situations where the storage could be synchronized, but not connected (will be fixed in the future build).

BenM · Wed Oct 22, 2025 7:52 am

Hi Yaroslav,

Perhaps I will have a look at this after we update the CVMs with the new build in a fortnight or so (School holidays are a pain, but someone has to take them!)

It would be nice to get CAU running again and not potentially breaking the cluster.

Ben

p.s. the clocks on the CVMs are still within 1s, so it looks like a win there!

Wed Oct 22, 2025 8:19 am

Hi Ben,
Yes, give it a shot. Let me know how it goes

BenM · Thu Nov 20, 2025 8:40 am

Hi Yaroslav,

Please to say that the CAU script just works when pointed at the CVMs - at least it does when one remembers that path names in CAU can't have spaces in them... and that the log file locations need changing wherever they are used.

I modified the script a little to add a "servers disconnected" entry to the log at the end, after all there is a log for the start of the script

Successful CAU run early this morning (finished at 0400 GMT ish) and the HA volumes are still synchronized and not doing a full sync.

Thu Nov 20, 2025 9:12 am

Ben,

Thanks for sharing

Yeah, I'm sorry, I missed that bit.