Very high load, apparently caused by pdflush

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http://serverfault.com – I have a server that's running CentOS 5, and it will periodically (a couple of times a day) have enormous spikes in load, and the whole server will grind to a halt. After a couple of minutes, the load will go back down and everything returns to normal. I suspect it has something to do with I/O and maybe a bad disk, but as the disks use hardware RAID, I'm not sure how to find out what's going wrong (smartctl just says "Device does not support SMART"). So anyway, what I see from top is: top - 08:51:03 up 73 days, 7:45, 1 user, load average: 69.00, 58.31, 46.89 Tasks: 316 total, 2 running (HowTos)