I've started to notice a ticking sound emanating from my WD2500JB. It is not alarmingly loud. The sound seems to occur only when the drive has been idle for some time, and will cease upon (some?) disk activity. The sound has a regular, steady cadence of somewhere between about 4 and 6 ticks per second.
I'm not entirely certain that it just started making these sounds, since I previously had the drive — mounted in a USB enclosure — stored out of earshot, and only recently moved it to where I can hear it.
The SMART attributes for the drive do not indicate any problems.
I did have some errors to clean up recently (since I started noticing the sounds). The errors occurred on an ext3 filesystem. The drive had been powered down while mounted a few times prior to that
Is this cause for alarm? Should I scrap the drive on principle?