Raid Performance Issue

Jerry Gardner · n00b Joined: 04 Apr 2003 Posts: 62

I built a new system to replace my aging Win2K Server as my main file server for serving up streaming video.

The Windows box has performed well in this task with nice smooth video and no glitches or dropped frames. Unfortunately, I can't say the same about the new Linux box. Streaming video from this box is very jerky and often drops frames.

This is puzzling to me because the Windows box is a 700 MHz PIII with 512MB RAM and a 100 Mb/sec Ethernet connection to my network. The new Linux box is a dual 2.4GHz Opteron with 2GB of RAM, a 1TB raid array (software raid-5) formatted as XFS, and a 1Gb/sec Ethernet connection. The Linux box is running Samba 3.014 and kernel 2.6.12.

Is this a tuning issue, or is Linux/Samba just unable to sustain the same data rate serving files as an old Win2K server running on far inferior hardware?

6D7474 · Tux's lil' helper Joined: 08 Sep 2005 Posts: 135

well, maybe try checking what are the results of running hdparm -tT on you raid...

anonybosh · Guru Joined: 20 Nov 2005 Posts: 324

When copying a large file directly (not remote streaming) from both the Win2k box and the linux box, what kind of transfer speeds do you average?

Jerry Gardner · n00b Joined: 04 Apr 2003 Posts: 62

# hdparm -tT /dev/md0

/dev/md0:
Timing cached reads: 3364 MB in 2.00 seconds = 1681.41 MB/sec
Timing buffered disk reads: 424 MB in 3.00 seconds = 141.17 MB/sec

Are these numbers reasonable?

6D7474 · Tux's lil' helper Joined: 08 Sep 2005 Posts: 135

yes they seem ok, so i don't think it's a hard-drive configuration issue.
it might be a samba problem, but as i don't use it, i just can't help you with that...