When should I add a new host to my datacenter? 1

[ZipperHeadMan]

We are an medium size organization.
Currently we have 2 ESX hosts
Each run 2CPU w/ 32GB memory.
Memory usage on each hovers around 15Gb.
We run around 20-25 vm's in production.

When do I know its the right time to add a third host to my datacenter. My concerns are with HA being available should something happen as it's configured now. Are there any guidelines somebody can point me to?

Thanks.

 

[baddos]

12 1/2 guest per host isn't bad. Provided your IO and CPU are inline you should be fine with those 2 machines. You can probably add more memory to them and add some more guests even.

 

[Roadki11]

I would look at it like this. If you lost one of the hosts, can the 1 remaining host run all the critical guests until you get a replacement host? If the answer is no, then I would buy a 3rd host.

RoadKi11

"This apparent fear reaction is typical, rather than try to solve technical problems technically, policy solutions are often chosen." - Fred Cohen

 

[mrdenny]

Roadki11 hit it the nail on the head.

Denny
MVP
MCSA (2003) / MCDBA (SQL 2000)
MCTS (SQL 2005 / SQL 2005 BI / SQL 2008 DBA / SQL 2008 DBD / SQL 2008 BI / MWSS 3.0: Configuration / MOSS 2007: Configuration)
MCITP (SQL 2005 DBA / SQL 2008 DBA / SQL 2005 DBD / SQL 2008 DBD / SQL 2005 BI / SQL 2008 BI)

My Blog

 

[ArizonaGeek]

I'd agree above, Roadki11 hit it on the head. Look at your memory, CPU, network and disk utilization and if any are consistently over 50% than add a third host.

Cheers
Rob

The answer is always "PEBKAC!