Chris Stark wrote:
Hi,
I have a LSI MegaRAID i4 running in RAID 5 mode with 4 x 120 GB ATA
drives as my "/home" partition. The write performance is deplorably bad
(5 MB/s) but what's worse is that the system load shoots up to 15.0 or
even higher when I transfer any file that takes longer than a couple of
seconds. The system has quite a bit running on it (usually around 100
processes), but the load normally averages around 0.02 - 0.8 (when not
transerferring files).
I'm running FC3 and the system is a dual PIII 800 MHz, 1GB RAM, 20 GB OS
drive, and a Linksys Gigabit Ethernet card. The read performance isn't
too bad (~ 40 MB/s), and I know that RAID 5 brings _some_ performance
penalty to writes, but 5 MB/s seems ridiculous, especially considering
the high system load.
Also, for what it's worth, FC3 didn't detect the "megaraid" driver quite
right (it autoloaded the newer "megaraid_mbox" driver which doesn't
recognize the i4's logical drives -- I had to manually edit
/etc/modprobe.conf).
Any ideas how I can further troubleshoot this issue?
Try adding elevator=deadline to your kernel line in /etc/grub.conf and
reboot.
