FC4 almost totally unresponsive under heavy disk IO...
Here's my config, running FC4 x86_64 SMP:
ABIT SU-2S motherboard
Dual Opteron 246
2 gigs ECC RAM
2 Maxtor 300 gig Maxline IIIs in RAID-0
Onboard Marvell 88SX6081 SATA-II controller
Whenever there is any heavy disk I/O (such as copying/uncompressing large files), everything else comes to a screeching halt...Dovecot connections won't even respond at all...Top shows no unusual processor loads, so it must be completely clogging up the bus somehow...
Disk performance shows as:
Timing cached reads: 3808 MB in 2.00 seconds = 1903.88 MB/sec
Timing buffered disk reads: 372 MB in 3.00 seconds = 123.83 MB/sec
My guess is that this has something to do with the Marvell driver, which is proprietary. The controller is not supported under the kernel/libata...
Am I on the right track here? I can't think of anything else that would be causing this...Luckily I rarely see the kinds of disk loads that cause this, but even so, it renders my server useless when I do...