Pretty poor and random performance

[Crispin]

Hi Folks,

I've finally got around to setting up the new NAS but am confused by the performance.
At best, I am getting 20MB/s on write. The funniest was 280KB/s.

Hardware is an ASUS with AMD 350 pro on (set to supa-fast in the bios :p) and a 1Gb broadcom NIC. I'll be trying an intel one next.
Disks are 4 x 2TB RAIDZ with a 60GB SSD as cache.

While copying, smb is top user but only at 24%.
I've installed the release version.

While I'm not expecting the performance I used to have when using the hex core AMD, I think this is a bit slow.

I'll see tonight what the actual disk speed is like.

cheers,
CP

 

[William Grzybowski]

How much ram? Did you install amd64 version?
Did you test it locally?
The 2TB drivers are probably 4k and 8.0-RELEASE may not be detected it and they are working as unaligned as of 512b

 

[Crispin]

ram would have been helpful... ;)
8GB (max of board) and yes, it was the 64bit install.


time dd if=/dev/zero of=/mnt/tank/file bs=256k count=32768
0.015u 0.599s 0:00:61 98.3%

time dd if=/dev/zero of=/mnt/tank/file bs=256k count=327680
0.195u 5.813s 0:06:61 98.3%


reading:
time dd if=/array/file of=/dev/zero bs=256k count=32768
0.000u 0.258s 0:00:26 100%

how do those numbers look?

time dd if=/array/file of=/dev/zero bs=256k count=327680
0.015u 0.238s 0:00:25 96%


I am now trying to get what data I put on off and "back to safety" as I can't say I am comfortable with this as it sits.
I am managing to copy off at 600KB/s (yes, KB)


edit:

the 2TB disks are the Samsung F4s which, depending on what you read, seem to either be 4k emulation or not. My understanding was that, if that is the case, you would not have any benefit as the 4k was emulation.
I did try beta2 and the 4k stuff but I could not get it to work properly. A fault I later discovered, after reinstalling release, was actually my windows box. (since reinstalled win7)
4k or not, that should not hit it this badly?
A reboot (old windows hand) of freenas and I now have it to 8MB/s on read (cutting off nas share, so, a delete?)

 

[William Grzybowski]

I am not really seeing any number results from DD
you dint paste the throughput

4k disks should perform bad if not aligned.. something like 10mb/s I guess, but not as bad as less than 1mb/s...

 

[matthewowen01]

in the future, don't 'time' your dd command, it will do it for you. but that doesn;t sounds like the issue.

can you run the following and post the output:

zpool status

that will tell us how the drives in your pool are doing.

 

[Crispin]

don't have it to hand but the status shows the 4 disks, raidz, with the ssd as cache, it's online and fine with no errors.
When I did the dd, the iostat -v showed all the disks getting hammered so there is some joy there.

I've since removed the SSD as I am now trying to get my data off, thinking that it might be a problem. Copying 800G off the array is going to cause the cache to cycle a lot. No joy.