Cisco UCS B200-M1 vSphere Virtual Machine Density – Upgrade Time!
Our Cisco UCS system has been running in production for a while now. Since we have continued to grow, we are now at at a point where a RAM upgrade is having to be pushed through our purchasing process.
Having limited funds during our initial UCS purchase, we were only able to fill our B200-M1 blades with 4gb RAM modules. Below is an image showing the current RAM to CPU utilization.
vSphere RAM Usage
I have put out a few previous posts concearing consolidation ratios here:
http://blog.colovirt.com/2010/05/24/cisco-vmware-cisco-ucs-b6620-vmware-consolidation-ratio/
http://blog.colovirt.com/2010/06/01/cisco-vmware-cisco-ucs-b250-m1-vmware-consolidation-ratio-oracle-dbs/
A recap of our current setup is below.
| 6 | VMware ESX B200-M1 hosts |
| 294 Gigs | of RAM total |
| 48 Gigs | of RAM per server |
| 119 | Total Virtual Machines (VMs) |
Density = ~19.8 VMs per B200-M1 server w/48g of RAM
Again, this is a mixed environment containing host OSs:
- Windows 2003
- Windows 2008
- RedHat Linux
We have stopped deploying any VMs in this cluster due to RAM constraints. Thankfully our RAM upgrade is being shipped out currently from Cisco.
This will be a total replacement of the 4gig RAM modules currently installed in the B200′s with 8gig sticks.
Ordered 60 x 8gb sticks = 480gig upgrade (total) to ESX hosts
Of course our 4gig modules will not be wasted. They will be used to fill our B250-M1 servers to maximum capacity (number of RAM sticks).
This upgrade should get us through until another UCS chassis can be purchased next year. My advice for anyone who is planning on deploying UCS for the sole purpose of running VMware:
- Bite the bullet and go with the 8 gig sticks from the start if deploying only B200 blades
- B250 1/2 populated with 4 gig sticks = 98gigs of RAM. You can put 192 gigs of RAM in using 4gig sticks or 384gigs with 8gig sticks
- Keep at least one spare server in each UCS chassis for un-planned expansion or to use if another blade dies
