Tracking Down Load

I have a CentOS box here that is causing some strange load. Brand new X3230 (4*2.66Ghz), 2GB ram and 2*500GB SATA2 in raid-1 on a LSI MegaIDE controller.

Basically the server is continuesly at a load of 1. However I dont see why. No CPU load, and no IO as far as I can see. Does anybody have a tip where to look for the problem?

Quote:

top - 05:01:56 up 1:53, 2 users, load average: 1.00, 1.02, 1.20
Tasks: 81 total, 1 running, 80 sleeping, 0 stopped, 0 zombie
Cpu0 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu1 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu2 : 0.0%us, 0.0%sy, 0.0%ni,100.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Cpu3 : 0.3%us, 0.0%sy, 0.0%ni, 99.7%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 2072132k total, 591072k used, 1481060k free, 65652k buffers
Swap: 2048276k total, 0k used, 2048276k free, 461532k cached

Quote:

# iostat
Linux 2.6.18-53.el5 (xxxx.xandrios.net) 05/14/2008

avg-cpu: %user %nice %system %iowait %steal %idle
2.65 0.56 5.56 0.97 0.00 90.26

Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 6.44 99.67 255.89 686581 1762792

Quote:

# hdparm -tT /dev/sda

/dev/sda:
Timing cached reads: 16092 MB in 2.00 seconds = 8057.39 MB/sec
Timing buffered disk reads: 88 MB in 3.04 seconds = 28.92 MB/sec

With the WHT benchmark test the machine scores about 520 points, seems not bad either.

Only thing I could think of is that it has something to do with the raidcard. The data transfer rate is quite low. Could it be that the card is rebuilding the array? Can I check that without rebooting?