Saturday, June 25, 2011

Creating a VMware Virtual (Home) Lab for VMware VCP & VCAP - Step Three: HA Funny Stuff

This article is part of my Virtual Lab Series.

In the first part of this series I discussed the over all design of this lab.
In the second part of this series I discussed how I installed ESXi.
In this third part I discuss some of the quirks of VMware HA I encountered.

I'm finally getting around to picking up my virtual lab again.  Due to work commitments I really haven't had any time to dedicate to the lab recently.  Right after I finished the previous article, I couldn't get HA to configure.  I created a cluster but if I added the hosts and tried to enable HA, it would fail.

The first error was around memory allocation...  uh oh.  Looks like the memory tweaks in my previous article don't hold up if you want to enable HA.  I bumped up the memory to 2GB and the memory allocation error went away but I still had a super generic error message: HA agent on in cluster in has an error: Cannot complete the HA configuration

Great... All the usual tricks didn't work (remove the host, add it back, enable HA again, double check DNS, etc). Finally, I bumped the memory to 2.5 GB, still nothing. As a last resort I reinstalled and made the local disk 10GB instead of 5GB (and kept the memory at 2.5 GB just because I can).

It worked! I reinstalled the second host and it also worked the first time. Due to the overall quirky nature of VMware HA (HA and I have a long history together and it's not all good) I can't say for sure if either the memory or disk change did the trick but I thought I'd pass it along.


Andy Grant said...

Don't you love it when you make two changes and can't tell what made the difference :)

I have encountered the same HA error in the lab you mention and the safe-bet I have gone with is 3Gb RAM for my nested ESXi hosts. I didn't try 1/2 Gb increments.

I have used as little as 2Gb for storage sucessfully.

Aaron Delp said...

Hey Andy! I couldn't agree more. The sad part is I just don't feel like troubleshooting it right now. My experience with HA has been that it is usually easier to just scratch install the whole OS. Sad but true. Thanks!