SSD pool and performance impact

[Kean]

I'm looking for a SSD drives to setup small pool for VM storage. I selected few Intel (Intel DC S3710 or S3610) or Toshiba (HK4R) enterprise models to build it. I would start with 2 drives in mirror. Then if my demand will increase (both capacity and IOPS/tput) i would like to rebuild it and create 2 strips and 1 mirror based on them.

Now the questions:
1. What do you think about those drives?
2. What performance can I expect based on single mirror (2 drives) and then mirror on strip (4 drives)?
3. Whats the rule of thumb to calculate read and write throughput in mirror? I found this article and seems write t-put will not increase adding new drives, but read will be multiplied by drive count. Is it right?

 

[MatthewSteinhoff]

We use the cheapest SSD drives we can find for our VM storage pools. Remember: the 'I' in RAID is for 'inexpensive'.

SSD performance is so much better than conventional drives - especially in terms of IOPS - we determined we didn't need top-tier drives. We have a striped mirror using four ADATA 960G drives that are about two years old. If we were buying today, we'd probably go with Samsung EVOs.

What's an 800G Intel DC S3610 for these days? $400? I could get a pair of 1TB EVOs for $300. For less then the cost of two S3610s, I could buy four EVOs and have better performance (striped mirror - double the bandwidth and IOPS) or have a triple mirror with a hot spare if reliability were paramount.

So, long story short, buy cheap SSDs for storage pools.

Cheers,
Matt