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Thread Starter 
Hello everyone.
Most of you know that I have (and love) Dell C1100s. I'm also a big fan of Hyper-V and that is my preferred virtualization platform. The Dell C1100 is a great server for me fitting my needs, and Server 2012 R2 brought new enhancements to both Hyper-V and Storage Spaces.

Storage Spaces has, effectively, allowed me to eliminate the need for iSCSI storage for my virtualization boxes, and allows me to use local storage with great efficiency. Before I rebuilt my primary C1100 with Server 2012 R2, I was running Server 2012 and using Storage Spaces with 2 x 2TB (Toshiba DT01ACA200) drives in a Mirror Space. Performance was pretty good, and I could run 12-15 VMs before I started to feel IOPS issues that were really noticeable. With Server 2012 R2, Storage Spaces was updated with Tiered storage which allows the used of SSDs to sit in front of slow storage (i.e., cheap 7200RPM SATA drives). Now the first big distinction to make is that Tiered storage does not set your SSD to cache data, but live data also lives on that SSDs. Caching would make all writes write to the SSD first, and call the write complete, then move that data to slow storage in the background. This is a feature I would like to see since, however, and I would like to set up a 2 x 2TB drives in a Mirror with a SSD in front of it for caching. With Storage Spaces you can set up journeling, but I don't think that that's quite the same thing. Anywho, Tiered Spaces could allow you to have 2 SSDs in a Mirror in front of 2 7200RPM drives in a Mirror, and add that storage together (2 x 60GB SSDs plus 2 x 2TB 7200RPM drives would yield 2.06TB) of usable storage. The downside is your Tier 1 storage (SSDs) has to be the same array type as your Tier 2 storage (HDDs), so both have to be either Simple Spaces, Mirror Spaces, or Parity Spaces.

Since the C1100 only has 4 drive bays and I use a 60GB SSD for the boot, I have only 3 drive bays free so using a Tiered Mirror Space wasn't possible (unless I mod the case to put the boot SSD in the chassis, which I didn't want to deal with). For this setup, I originally bought 2 2TB DT01ACA300s and a 120GB Mushkin Enhanced SSD. I first wanted to try and see if I could put the 2TB drives in a Mirror Space, and have the SSD in a Simple Space in front, but it would not allow that. My strategy has since been changed to 1 120GB SSD and 1 2TB 7200RPM drive. Long story short, the Tiered Space yields performance on par with the SSD as long as the writes are less than the size of the SSD (120GB), which is what it will mostly be in my case. Testing with a file over 120GB will see performance in between the SSD and a single 7200RPM drive.

Overall, I am happy with the setup, and have some testing numbers to show. I used ATTO to show Sequential R/W speeds, and SQLIO to show random read speeds (aka, IOPS) at 8Kb and 4Kb chunks of IO over 60 seconds. I should have tested with 64Kb chunks of IO as well, since that is what is common with Hyper-V and VM storage, but I did not. The point is to show comparison of storage between a single SSD, a single 7200RPM DT01ACA200 drive, two DT01ACA200 drives in a Storage Space Mirror, and the SSD and 1 DT01ACA200 in a Simple Tiered Storage Space. All SQLIO tests were completed with a single 50GB file.

One thing to note, which I haven't confirmed, but it appears that the C1100s use SATA II for internal connections since the SSD capped out around 275MB/s. The same model SSD (but in 60GB) in my NUS server caps out around 550MB/s.


ATTO ScreenShots (Click to show)
Single 7200RPM Drive (Toshiba DT01ACA200)


Single 120GB Mushkin Enhanced SATA III SSD (MKNSSDCR120GB-7)


Storage Space Mirror with Two (2) 7200RPM Drives (Toshiba DT01ACA200)


Tiered Simple Storage Space with Single 120GB SSD and Single Toshiba DT01ACA200)
SQLIO PowerShell ScreenShots (Click to show)
Single 7200RPM Drive (Toshiba DT01ACA200)


Single 120GB Mushkin Enhanced SATA III SSD (MKNSSDCR120GB-7)


Storage Space Mirror with Two (2) 7200RPM Drives (Toshiba DT01ACA200)


Tiered Simple Storage Space with Single 120GB SSD and Single Toshiba DT01ACA200)


SQLIO Chart:



So there you go. Let me know if you have any questions, or if you would like me to test any differently. I want to run the same SQLIO test using 250GB file in the Mirror and Tiered Spaces, and I also want to redo the SQLIO tests using 64Kb IO chunks. I may get around to doing those anyway, and I would update the above info.

Thanks!
Edited by tycoonbob - 10/26/13 at 10:13am