monitoring hard drive activity ?

[maccatalan]

Hello.

I reinstalled Tiger, clean install, made all updates, but now I notice a highly increased activity of my external hard drive. And I don't understand why. Spotlight is not indexing it and no applications are open.

So here is my question:
Is there a way to know what files are being written/read on a hard drive ?

I know that going to the Activity Monitor we can get what files are used by a given process. But here I don't know what process to monitor, so I was wondering if there was a way to list/monitor all hard drive activity from the command line or any simple utility you know. (we will avoid writting our own program that registers to the kernel events notifier ;-) )

Thank you,
Pierre.

[maccatalan]

before reinstalling my system I did lots of 'rm' on that external hard drive ... do you think the system would still try to keep track and clean all these previous actions ? (it's a journalized HFS+ volume) That would be amazing and very long/slow in time !

[ElDiabloConCaca]

Spotlight may indeed still be indexing that drive -- just because Spotlight allows you to search the drive and appears to be finished indexing it doesn't mean that it's totally done -- it will still go back and import other information from the files for a more complete Spotlight index. It may be indexing content from text/PDF files, or EXIF data from photos or optimizing the Spotlight database on that drive.

Running "top" in the Terminal, do you notice a process called "mdimport" taking up a few CPU cycles?

[dichimac]

In my macbook pro (Snow Leopard) there is an intermittent writing activity which doesn't let the hard disk go to sleep: I tried to see what's happening with sudo fs_usage, and I found out that past every 30 seconds the same series of processes is repeated; here is a single instance:
20:41:08.188 WrData D=0x00007c39 B=0xa000 /dev/disk0s2 0.033631 W launchd
20:41:08.215 IOCTL <DKIOCSYNCHRONIZECACHE> /dev/disk0s2 0.027190 W launchd
20:41:08.216 WrData D=0x00004a88 B=0x200 /dev/disk0s2 0.000699 W launchd
20:41:08.216 sync 0.316780 W launchd
20:41:08.216 select S=1 30.316916 W KernelEventAgent
20:41:08.217 sendto F=4 B=0x1 0.000015 KernelEventAgent
20:41:08.217 getfsstat64 0.000004 fseventsd
20:41:08.217 getfsstat64 0.000011 fseventsd
20:41:08.217 select S=1 0.000168 W KernelEventAgent
20:41:08.217 recvfrom F=5 B=0x1 0.000008 KernelEventAgent
20:41:08.217 WrMeta[async] D=0x0047e298 B=0x2000 /dev/disk0s2 0.000847 W launchd

Is there a way I can avoid this to happen and get my hard drive to sleep?
PS Yes, I did check the option "put the hard disk(s) to sleep when possible".

Macbook Pro, 3.06 GHz Core 2 Duo, 4GB RAM, 7200RPM 320GB HD