6x4TB 7200rpm RaidZ2 + 10Gb Performance

[akc360]

Hi All,

Looking for some reassurance on whether my array performance is up to scratch.

When data is in the ARC I can pull from freenas at about 970MB/s however when pulling a large file (~50GB) that isn't in the ARC transfer settles at between 200-300MB/s.

My question is, should I be seeing more sequential performance from 6x4TB 7200rpm RaidZ2 drives?

Freenas 9.2.1.4
Xeon x3440
32GB RDIMM ECC
6x4TB 7200rpm RaidZ2
Qlogic 10Gb Nic

Connected Workstation:
Windows 8.1
intel x3820
16GB RAM
Revodrive x3 960GB
Qlogic 10Gb Nic

Anyone else with similar setup?

Thanks in advance,

Alex

 

[cyberjock]

Well, two things:

1. There really is no such thing as "sequential" with ZFS. So your question really isn't valid. But, I know what you are trying to say, and I wouldn't expect more than about 600MB absolute best-case from that pool.
2. I run 10Gb and despite the fact that I can do over 1GB/sec on my pool it fluctuates from 50MB/sec all the way up to about 800MB/sec.

Other then that I can't really say much. Qlogic isn't our most recommended card for 10Gb and it may be adding some kind of latency that is causing some kind of snowballing effect giving you slower performance than expected.

To be honest I'd just say "this is what it is" and go on with life. Some files will be faster and some will be slower. There's alot of things that affect throughput and unless you want to spend a few weeks learning the ins and outs of ZFS you aren't likely to touch a significant number of possible causes (assuming there is even a problem).

 

[akc360]

Thank you Cj, I won't worry about it then. I have some Intel x520 10Gb NICs around so I will try them.
If I did want to learn the ins and out of ZFS performance for free should I just read the forums here or can you recommend a good resource.
Thanks for the help and advice,

Alex

 

[cyberjock]

The only good source I know of is to read our manual and my noobie guide. If you've done all of those things properly then I'd say its just a fact with your hardware for whatever reason.

You could try looking to see if a disk is failing or if your disk subsystem just sucks. If you aren't using an IBM M1015 in IT mode you are probably missing out.