Thursday, February 24, 2011

Big VMs Aren't What They Used To Be

I've had the privilege to work on some of the current generation Intel Westmere and Nehalem EX servers over the past few months.  This testing has focused on Oracle RAC (which has been pretty cool in lots of ways) and has involved what I would have considered to be very large VMs not so long ago.  My typical RAC node for testing is usually 4 or 8 vCPUs with 32 GB of RAM, and it turns out these are moderate or small in size.

When the server has 32 cores and 256 GB of RAM, a VM with only 8 vCPU and 32 GB is relatively small.  In fact I'm often running four of them at the same time and still find that performance is great.  Additionally, I'm using vMotion to move these VMs in a matter of minutes from one server to another.

I'm using these 8 vCPU VMs with 32GB of RAM the same way that I used 2 vCPU VMs with 8GB a few years ago.  They are no longer big VMs.  Can't wait to see what we are doing in a few more years.

1 comment:

effendi said...

I wonder how much it is people not tuning their workloads and optimizing the SQL. With tuning I've managed to reduce the CPU load on our EBS instance to roughly 10% of its original Oracle DB CPU load.

Even though it doesn't effect me currently, I do look forward to when vSphere VMs are not limited to 8 vCPUs and FT has multi-processor support. Anything to lower barriers to adoption.