Pretty cool right?
A little backstory – One of the things the End User Computing team inside the vSpecialist organization was tasked with was updating some of the tools, demos and various other “rules of thumb” type metrics we use when speaking to customers. A few weeks ago our team met with VMware, Cisco and Citrix to hear about their End User Computing strategy as well as to hash out some various sizing ideas when working with customers on VDI designs. Out of these meetings and discussion an idea was brought to the table to help our field teams and partners understand the value of features like FAST Cache when doing VDI designs. During one of our discussions, we decided that we needed to test a config that would 1) be easy for our teams to understand and recite when speaking with customers, and 2) be something we’ve tested and could stand behind. Out of that discussion, and in our best “Herman Cain” mantra we came up with 5, 5, 5, 2 for 500 desktops (non-persistent). That breaks down to:
- 5(ea) SSD/EFD Drives
- 5(ea) 15k RPM SAS drives
- 5(ea) 7200 RPM NearLine-SAS Drives
- 2(ea) SSD/EFD setup as FAST Cache (Read/Write)
- NFS Datastores
- VMware View 5 on vSphere 5
The first 3 drive types would be put into a RAID 5 (4+1) FAST VP pool (1 pool) and the 2(ea) SSD/EFD’s would be setup as FAST Cache (You can read more about both of these here). We were more than confident that this would work but we wanted to test it to see if we could push the number of desktops above 500.
Well, a funny thing happened on the way to testing. We were able to adjust our spindle count….DOWN!. The proof is in the pudding as they say, so the testing can be found on Andre Leibovici’s site (finish reading here then go to his site – he already gets enough blog hits ) but here is the breakdown of the Boot Storm he created and the spindle count used to test against it:
- 3(ea) SSD/EFD Drives (RAID 5 – 2+1)
- 3(ea) 15k RPM SAS Drives (RAID 5 – 2+1)
- 3(ea) 7200 RPM Near-Line SAS (RAID 5 – 2+1)
- 2(ea) SSD/EFD for FAST Cache. 100GB
- No Dedicated SSD/EFD for Replica’s – we just tossed the Replica into the FAST VP Pool.
- VNX with NFS Datastores
Now just to be clear, we are not suggesting that if you have a 500 desktop requirement that you should run out and buy this 11 drive system (but you certainly could). There are more things you need to focus on other then just the desktop number. We focused on performance and not capacity so you will want to pay attention to that. BUT, C’MON !! How about that for a problem to have when designing for VDI !! Also, when I spoke to Andre who headed up the testing, he mentioned that during the testing the NL-SAS drives never got touched so technically we ran this config on 6 Spindles plus 2 SSD/EFD’s in FAST Cache. If you are adding that up at home, that’s 8 spindles for 510 non-persistent VMware View 5, Windows 7 (32bit) desktops.
At the end of the day, driving down the cost of Virtual Desktops is one of the key things we try to do when designing VDI solutions. Storage (specifically spindle count) is usually one of the top line items when doing this. The value of FAST Cache type features that can utilize SSD/EFD’s as a read and write caching can really help drive the spindle count down. When you drive the spindle count down, you drive down the costs of the array. This helps drive down the costs of the VDI deployment.
At the end of the day, this is a HUGE win for companies looking to do virtual desktops but were concerned about the storage costs.
Dare I say, 2012 is the year of VDI