Ceph SSD recommendations

[troycarpenter]

I have been dragging my feet on this one, but I am looking for SSD recommendations for my Ceph servers. Currently each server has ten 5TB spinner drives with SSD Cache drives. The performance has been decent, but there are many times where guests give IO errors due to occasional high wait times. The servers have SATA/SAS drive interfaces.

What drive recommendations are there, and where should I look. I would like to maintain the same storage capacity as possible, but I also understand that 5TB (or thereabouts) SSD can be pricy themselves, let alone having to buy 30.

Thanks

 

[aaron]

Anything enterprise/datacenter rated. Look for real power-loss-protection with capacitors. Even the worst of those should give you decent performance and are not that much more expensive than good consumer SSDs.

 

[troycarpenter]

Thanks!

 

[dignus]

In my experience best for the buck are Samsung drives. Something like the PM893 will do the job perfect. Sure .. other brands might have better performance, but price/quality is great on these drives.

 

[troycarpenter]

Revisiting this. I've looked at the PM893 but at SATA3 it tops out at 6Gbps. Is it worth it to try to find SAS drives, that should top out at 12Gbps?

 

[Kenzi]

Depends on your network speed. 10 drives *6 is 60gbps, so if your network is faster than that you could consider faster drives.

 

[Dunuin]

And probably mostly useful for reads as the write speed should drop quite fast, as soon as the caches get full, to lower levels not capped by SATA throughput anyway.

 

[troycarpenter]

I'm using a 100Gpbs network for Ceph storage and am using a SSD cache drive for the OSDs in each chassis.

 

[mfed]

Hi @troycarpenter

Would you mind to share what kind of SSD cache configuration you are using?