My new Ubuntu 9.04 DIY NAS is slow...

[MrRalph]

Hi all, I just assembled a DIY NAS with

- Gigabyte GA-MA74GM-S2H mobo
- 2x 1Gb Ram DDR2 667
- AMD 4050e processor
- 1x Seagate MOMENTUS 7200.4 160GB SATA for OS
- 3x WD10EADS 1Tb configured for RAID5 (/dev/md0)

Just a basis setup. Copying a pictures folder (1Gb in total) from /dev/md0 to /dev/md0 speeds at around 22Mb/sec. I think that terribly slow. Hdparm gives 168Mb/sec for buffered disk reads.

What's the next thing I can/should check for this?

Ralph

 

[msl]

Why do you care about the performance of copying a file on the RAID array to another location on the same RAID array? This is going to produce lots of contention and seeking as the copy reads and writes to different locations on the same disks, so you would expect the performance of this operation to be relatively slow.

For a NAS device my guess is that you care more about the performance of copying a file from a remote machine to the NAS, or copying a file from the NAS to a remote machine. If this is the typical usage scenario you care about then you will get more useful results by testing this scenario.

 

[00Roush]

You might consider trying to test speeds with Iozone or Bonnie. As MSL mentioned writing to the same RAID 5 array that you are reading from could be causing the slower than expected speeds. Although I wouldn't expect it to be that low. I assume you are doing this copy locally on your NAS and not from a client computer.

00Roush

 

[MrRalph]

I tested with Iperf, both with and without a file. Client side was Vista SP1.

First without the disk subsystem:

------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 8.00 KByte (default)
------------------------------------------------------------
[140] local 192.168.1.99 port 5001 connected with 192.168.1.95 port 44913
[ ID] Interval Transfer Bandwidth
[140] 0.0-10.0 sec 111 MBytes 92.6 Mbits/sec

And with a 10Gb large file.

[ ID] Interval Transfer Bandwidth
[152] 0.0-10.0 sec 98.9 MBytes 82.7 Mbits/sec

Copy with Windows shows around 30Mb/sec.

Is there any suspect component here?

Thanks, Ralph

 

[MrRalph]

I finally solved the issue. I changes the SATA controller setting in the BIOS from IDE-emulate to AHCI and everything speeded up. Copy from to is now a steady 52Mb/sec and all other parameters perform well.

Intel Performance Test Toolkit:

( HDVideo_1Play )
Average Throughput: 53.104MB/s
( HDVideo_2Play )
Average Throughput: 68.328MB/s
( HDVideo_4Play )
Average Throughput: 57.962MB/s
( HDVideo_1Record )
Average Throughput: 70.511MB/s
( HDVideo_1Play_1Record )
Average Throughput: 66.646MB/s
( ContentCreation )
Average Throughput: 27.661MB/s
( OfficeProductivity )
Average Throughput: 28.876MB/s
( FileCopyToNAS )
Average Throughput: 56.588MB/s
( FileCopyFromNAS )
Average Throughput: 50.328MB/s
( DirectoryCopyToNAS )
Average Throughput: 15.230MB/s
( DirectoryCopyFromNAS )
( PhotoAlbum )
Average Throughput: 21.862MB/s