SCSI HD access noise?
 

I'm using SuSE 9.2 Pro/KDE on a homebrew box with two IDE hard disks, and one SCSI hard disk which is where "/" resides. About every three seconds, I hear a short (1-2 secs.) burst of chatter from the SCSI disk, as though some sort of read/write were happening, even though the machine appears to be idle. This occurs whether or not I'm connected to the WAN, and whether or not X Window is running, though if X is NOT running the noises from the hard disk happen less often, say, about every 6 seconds. The disk access light doesn't come on, because the SCSI disk, for some reason, doesn't seem to trigger it; only the IDE drives activate the light.

I haven't been able to figure out a way to see what the disk/system is up to. If someone knows how I might go about this, using some utility or other, I would be grateful to hear about it. I can't really tell anything useful from ps, or top, let alone lsof. I'm suspicious that KDE is somehow involved, but again, I can't figure out how to check.

Thanks in advance,
Denis