I have noticed that the 'update' process is keeping my hard drive from sleeping. The process accesses the disk every 30 seconds or so, and when I leave the computer for a while I can still hear the drive spinning when I come back. If I quit update from the activity monitor the drive goes to sleep after about 5 minutes of inactivity. On another mac I have, update is running but it does not cause this problem. On this mac it does this even when no applications are running, so I put it down to update being at fault.
I have had a look what update does and found that it is "responsible for keeping disks synchronized with the file system cache, to keep data loss to a minimum in case of a crash."
I have not had any crashes, but at the moment it is is more likely to cause a crash by wearing out the drive prematurely.
Can I reinstall update to make it behave like the one on my other mac, or could I disable it altogether?