I'm fairly new to ESX generally and we're currently using ESX 3.5. I understand that quite often virutal machines don't need as many resources as you'd think and I'm getting to grips with memory requirements presently.

We've got some Windows Server 2003 VMs and initially they were assigned the normal amount memory that a seperate physical server would need, but it's becoming apparent that they don't seem to need anywhere near that.

For example a server with MSSQL 2005 installed was originally given 1GB memory, then it's become apparent (from viewing VM memory performance) that it could probably run on 256MB generally, which is a really small amount for a MSSQL server, even if it's under a small load. It's a really small amount for a plain Server 2003 OS!

Memory allocation is porbably quite a big subject (too big for a reply to this) but if someone could point me in the direction of how to get the best out of ESX and VMs is regards to memory, that would be great. It seems tuning these things is a bit of an art in itself......

Cheers,

Tim