Adding Disk group is taking forever...

[juchestyle]

Hey Everyone,

We have a 4 node QA vSAN cluster we are using to learn and test vSAN before we implement our production environment.  Running only 13 VM's on it, most of those are HCI Bench VM's.  We have one Disk group on 4 hosts that consists of 3 capacity and 1 flash drives.  All drives are flash by the way.  We are trying to add a second disk group.  3 hosts added that super quick.  The 4th host has taken 15 minutes to add an additional disk group of 3 capacity and 1 flash. 

Flash drives are 784 Gigs

Capacity drives are 3.49 TBs

Any troubleshooting or logs we should check out on this?  Is this a valid concern?

[TheBobkin]

Hello juchestyle,

This procedure *usually* only takes at most a 1-2 minutes.

How much physical memory do these hosts have and ~how much is used by VMs on these hosts etc.? I ask as disk-groups require a certain amount of memory each and I have been unable to add them properly in my lab when there was insufficient memory:

https://kb.vmware.com/kb/211395

/var/log/clomd.log and vmkernel.log would be the best place to start.

Bob

[GreatWhiteTec]

That's a good point that TheBobkin​ brings up. I ran into this once, where not having enough memory prevented additional DGs from being created. Also, i have seen VC not reporting/refreshing correctly at times, especially when the VC is at a lower version than ESXi hosts. vCenter should always be at the same version or higher than hosts. You can check in the CLI of the host and see if the show up there (esxcli vsan storage list).