NAS seems really slow

[FlyingPersian]

Hi
I've been replacing some stuff in my Plex Media Server lately and in doing so I have to extract/move some stuff around. I've noticed that once I extract/move a movie my server gets really slow. Searching in Plex takes minutes sometimes and ruTorrent doesn't read files in the watch dir for quite some time. Also the stuff I have in my Plex library takes forever to load. Once the extraction is done everything becomes normal again. I don't think I had that before, so I'd like to know if there's anything I can do except upgrading my hardware.

I have 6 WD Reds 4TB in a RAIDz2 (I think :D) with an Intel G3220, 16GB RAM (I know I should have more, but I'm a poor student) and the newest 9.3 version of FreeNAS. Any suggestions?

 

[Bidule0hm]

How full is your pool?

 

[FlyingPersian]

It was at 90% 3 days ago, now it's at 87%. I'm working on reducing the stuff I have so near 75%. Is that the reason? It has been full like this for a while now, mostly around 85-87%, but as far as I remember it wasn't as slow as it's now. Again, it's only slow when stuff is being extracted, not when everything is on "idle".

 

[Bidule0hm]

Yes, don't search any further. ZFS switch from speed optimisation to space optimisation when you cross the 90 % limit. That's why it's recommended to not fill the pool more than 80 % (so you have time to expand it before hitting 90 %)

 

[FlyingPersian]

Okay and when will it become "normal" again? Below 80%?

 

[Bidule0hm]

Yes, but the fragmentation will still be here so don't expect too much though.

 

[FlyingPersian]

Can I do anything about the fragmentation? Right now I'm at 85% with a fragmentation of 10%. I think the fragmentation was at 13% before.

 

[jgreco]

Sure, but you might not like the advice. Running torrents or anything else doing lots of reading and writing tends to cause fragmentation on the pool. 10% isn't horrible but it also isn't great.

You may be able to reduce fragmentation somewhat by copying lots of stuff off of the NAS, removing it on the NAS, and then copying it back to the NAS. This tends to cause contiguous allocations to occur where possible and will reduce fragmentation. If you could do that to the entire pool all at once, you'd all of a sudden have 0% fragmentation.

 

[FlyingPersian]

Doing that isn't really an option :x My biggest drive in my PC is 1TB and it holds some stuff, so I have like 600GB free. And I have about I don't know how many TB of data, so I could try incrementally, but it'd take forever.

Edit: You said that having things that do a lot of reading/writing are bad for fragmentation. How bad is the effect of reading? I'm running SickRage and CouchPotato, which don't do that much reading I think, but also ownCloud, which does some reading I suppose. I also have a rsync script on my ownCloud jail that syncs all the files of owncloud to a second folder every 5 minutes, from which I sync the files encrypted to a remote server. The program doing that is called duplicity and it only uploads the things that are new. This is done once at 3, 4 and 5 a.m. respectively for three different folders I have. I suppose this isn't that much reading/writing, but the rsyncing every 5 miniute is :x Is it too much reading/writing or still okay?