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

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

nicwolff — Mon, 30 Jul 2007 16:26:41 -0800

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?

By: brettcar

brettcar — Mon, 30 Jul 2007 16:32:03 -0800

Quite possibily `lsof'?

By: puddpunk

puddpunk — Mon, 30 Jul 2007 16:32:22 -0800

Do you mean "lsof" - List Open Files?

By: puddpunk

puddpunk — Mon, 30 Jul 2007 16:32:53 -0800

Dag Nabbit, brettcar.

By: flabdablet

flabdablet — Mon, 30 Jul 2007 16:54:44 -0800

"top" might be useful too.

By: xil

xil — Mon, 30 Jul 2007 17:10:35 -0800

fs_usage sounds more like it.

By: kimota

kimota — Mon, 30 Jul 2007 18:25:00 -0800

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.

By: nicwolff

nicwolff — Mon, 30 Jul 2007 18:54:33 -0800

Yes, fs_usage! Thanks very much, kimota.

By: nicwolff

nicwolff — Mon, 30 Jul 2007 18:55:02 -0800

And xil.

By: vacapinta

vacapinta — Tue, 31 Jul 2007 00:33:24 -0800

I found fseventer to be much more functionally useful in this regard.