How can I see what applications are accessing the disk under OS X?

July 30, 2007 4:26 PM

I have a strong memory that there's an OS X command-line tool that can dump to the terminal a running log of all disk accesses, including which executable is reading or writing. It was very handy in figuring out what the Mac was doing when the disk was busy but the load was low. Does anyone remember what this was?
posted by nicwolff to computers & internet (9 comments total)

Quite possibily `lsof'?
posted by brettcar at 4:32 PM on July 30, 2007

Do you mean "lsof" - List Open Files?
posted by puddpunk at 4:32 PM on July 30, 2007

Dag Nabbit, brettcar.
posted by puddpunk at 4:32 PM on July 30, 2007

"top" might be useful too.
posted by flabdablet at 4:54 PM on July 30, 2007

fs_usage sounds more like it.
posted by xil at 5:10 PM on July 30, 2007

fs_usage it is; note that it requires root/sudo to run it.

lsof will only provide a dump of open files and which process has them open. fs_usage is a real-time 'stream' of read/write accesses to the file system. It's pretty neat to watch, in a geeky sysadmin way, if you never have before.
posted by kimota at 6:25 PM on July 30, 2007

Yes, fs_usage! Thanks very much, kimota.
posted by nicwolff at 6:54 PM on July 30, 2007

And xil.
posted by nicwolff at 6:55 PM on July 30, 2007

I found fseventer to be much more functionally useful in this regard.
posted by vacapinta at 12:33 AM on July 31, 2007