Storage Spaces vs Raid 6

gorb · Thu May 07, 2015 11:23 pm

I am in a tight situation. I need to provide 60TB of storage and I only have a chassis with 36x 3TB disks. I would prefer to do Raid 10, but I won't have enough space for the data. We will be using Windows Server 2012 R2 and hope to use SBM 3.0. Should I got with Storage Space or Raid 6 or even wait until I have money available to buy JBODs and do it right? I need about 6k IOPS. Additionally, I have a 192gb of ram available in each host. What is the best way to use that RAM? Can I create a ram disk for L2? Should I buy some SSDs instead? Thanks for your help.

Fri May 08, 2015 2:22 pm

What's StarWind Virtual SAN doing in this equation? Do you happen to have any interconnect diagram?

gorb · Fri May 08, 2015 3:12 pm

we have 14 hyper-v hypervisors connected to a IB switch and then 2x of these SMC storage chassis on IB as well that will most likely be running as SOFS w/ Starwind v8 and SMB 3.0 in a HA configuration.

Fri May 08, 2015 4:45 pm

So you use StarWind do do a back-end for SoFS right? If so you'd better stick with hardware RAID6 on every SoFS node. Storage Spaces are OK but $200 RAID would give you better performance (especially with NVRAM cache). Dell PERC.

gorb wrote:we have 14 hyper-v hypervisors connected to a IB switch and then 2x of these SMC storage chassis on IB as well that will most likely be running as SOFS w/ Starwind v8 and SMB 3.0 in a HA configuration.

gorb · Fri May 08, 2015 9:05 pm

The SMC chassis have LSI 2108 addon cards with 512MB cache and BBU. Why do you said it's better to do raid 6 than raid 10 with a SOFS?

Sat May 09, 2015 1:48 am

I did not say that! RAID10 is better in most of the cases. But expensive.

gorb wrote:The SMC chassis have LSI 2108 addon cards with 512MB cache and BBU. Why do you said it's better to do raid 6 than raid 10 with a SOFS?

gorb · Sat May 09, 2015 10:14 am

Okay, that makes more sense. So doing Raid 6 is not the end of the world, but Raid 10 would still most likely be the best way to go. We're at about 75% Read and 25% Write. Also, how much of the Ram would be ideal for use as L1 Cache? And what SSDs would you suggest and how many is optimal? Thank you!

gorb · Mon May 11, 2015 1:54 am

Okay I've done some reading over the weekend. It looks like for ram you suggest doing 1GB Ram for 1TB of storage. So we have around 60TB of data so 60GB of Ram. However, the storage servers have 128GB in it. If we give 16 to the OS can we just give the rest to Starwind's L1 Cache? As for the SSD it would seem that for 60TB of storage we want to do 8-10 TB of SSD? Give that this is going to be primarily for Hyper-V VM storage is that investment worth it? We're at about 75% write and 25% read.

Also I noticed we have licensing for 3 units with unlimited storage. Since we have 2 units in Replication can we run our backup software on top of the 3rd VSAN server and just run DPM and Amanda Backups to it?

Lastly, Do you have deployment documentation for all of this and anything on SMB 3 and SOFS?

Tue May 12, 2015 4:44 pm

Hi

You are welcome to use 112GB of RAM for L1 cache, but ensure, that 16GB is enough for OS.

Since we recommend that end user uses write-through caching for L2 and your usage is primarily writes, then SSDs could be waste of money.

Yes, you can run your backup software on top of the 3rd VSAN.

Here you go:
https://www.starwindsoftware.com/techni ... er2012.pdf
https://www.starwindsoftware.com/techni ... Out_FS.pdf
https://www.starwindsoftware.com/techni ... _nodes.pdf

Please visit our resource library for additional information https://www.starwindsoftware.com/resour ... ry?type=tp

gorb · Wed May 13, 2015 9:41 am

I am sorry I wrote that backwards. We're 75% Read and 25% write.

Wed May 13, 2015 4:34 pm

Now buying some SSDs makes sense