Excessive disk activity on two disks of a RAID-10 (SA 6404/MSA30)

[Nigel Campbell]

I have a Smartarray 6404 and a MSA 30 on a development machine with the configuration below. The array is configured in a single RAID-10 with all 14 drives. The drives are all Maxtor 72GB 10k units.

Even when the machine is quiet there is a lot of disk activity on drives 1 and 3 for no apparent reason; none of the fault indicators are going. I cannot see any evidence of large grown defect lists of large numbers of faults logged by the controller.


The question is: Is there some reason for this activity (an enclosure management function or some such)

System specification:
HP XW9300, 2x Opteron 280, 8GB RAM
1x Smartarray 6404.
6x internal drives (72GB 10k, mixture of ST373207LW and Fujitsu MAU3073NP, all HP firmware). Two are set up as a mirrored pair with the system on it one one channel, 4 are set up as a RAID-10 on the second internal channel.
1x external MSA-30 single-channel on the 6404
with 14x 72GB 10k disks (all maxtor). The disks are set up as a single RAID-10 volume.