Which is the faster, UFS og ZFS?

[nikj_dk]

Hello forum,

I am testing file transfer speed in FreeNAS-8.2.0-BETA4-x64 (r11722) with a platform with 6 Gb ram, Intel(R) Core(TM)2 Quad CPU Q9550 @ 2.83GHz and a 340 Gb hdd.

With the same disk (only one, no RAID!), I have first tested with a UFS volume, deleted that, and made a ZFS volume, and tested.

With the UFS volume, transferral speed is around 60 MB/sec, and with ZFS volume, the speed is around 5 MB/sec.

My question is: Is UFS 12 times faster than ZFS?

If it is a question of RTFM, which part should I read?

Have I missed a thread about this, please inform me.

When I do the same copying to a Windows Server 2008 r2, the transfer speed is around 68 MB/sec.

I have had a FN 0,7 server for some years, which I was very happy about. I really like FN 8, and plan to use it in production in my company.

Regards.

 

[cyberjock]

ZFS is designed for using multiple disks simultaneously. I'm not the least bit surprised that ZFS performance was terrible when it wasn't being used as designed. Although I would have expected better than 5MB/sec. /shrug

 

[jgreco]

No, that just seems wrong. ZFS is certainly designed to be able to take advantage of multiple disks transparently, but it should be reasonably zippy.

Are you sure you're not maybe imposing some other workload on ZFS? I don't know how old your "340Gb hdd" is, but I know that I started to get some really wild bad performance out of ZFS when using some slowish oldish (60-80MB/s) disks on an insanely fast (32GB Xeon E3-1230) platform. However, that was while I was pushing tons of data at ZFS and it was actually trying to write it. If your system is unloaded and only getting 5MB/sec, that seems wrong. Can you try running "gstat" to check to see how busy the disk is while you do this?

 

[nikj_dk]

Thanks to noobsauce80 and jgreco for the quick replies.

According to your comments, I have decided to install 3 1.5 Tb disks, and test again.

@greco Could you be more specific about "imposing other workload? What should I look for?

Regards.

 

[jgreco]

Anything else the NAS might be doing. For example, for the performance problems I've reported, they're often under extremely heavy, generated-from-the-CLI workloads such as writing zero-filled files as fast as possible. This caused ZFS to melt.

So for your scenario, the question is, could it have been doing something else at the same time? Does "iostat" (or the more "top"-like "gstat" command) show your disks as idle when you expect them to be, busy when you expect them to be, and just how busy does it show them to be when it IS busy? Do you have an idea of what your disk is really capable of, minus the filesystem overhead?

Are you sure there's not some other "stupid unrelated problem" like ethernet switch configuration issues? Tried running iperf to make sure network's healthy? You wouldn't be the first person to have fell afoul of bad ethernet autodetection or something like that.