Tracing Disk Activity

[Chuck Swiger]

Hanspeter Roth wrote:
> I have set an idle timeout for the hard-disk. But when there is no
> user activity there are frequent disk accesses.

Yes, this is Unix.  Even when there is no user activity, a Unix system 
normally is still running a number of daemons such as syslogd which regularly 
write to the filesystem.  Beyond that, the syncer mechanism tries to reduce 
the number of dirty memory buffers every thirty seconds or so.

> How can one trace disk access?
> I'd like to know the kind of access and on which files/directories/
> nodes. I'd like to log on the console or on a memory disk file.

If you ask this question in the hopes of shutting down disk access long enough 
to permit your drives to spin down, then please be aware that such an answer 
won't help.

Instead you probably will need to mount filesystems read-only and create RAM 
disks in a fashion similar to booting off limited-write media like Compact 
Flash.  Either that, or simply shutdown the system or run zzz to suspend the 
system via APM/APCI.

-- 
-Chuck