Comments on: Linux: Find Out How Many File Descriptors Are Being Used

By: Matt

Matt — Thu, 25 Aug 2011 04:22:23 +0000

Because lsof counts files in /proc//fd and adds the opend shared libs from /proc//maps

By: avajadi

avajadi — Thu, 26 Aug 2010 14:51:52 +0000

cat /proc/sys/fs/file-nr shows number of open files in the first column, max allowed open files in third column and 0 in the second column.

It doesn’t update the first column on a single file handle basis, but seems to increase and decrease in steps

By: SparK

SparK — Wed, 11 Aug 2010 07:52:41 +0000

Yeah you can combine them all!
below one gives all type of descriptor opened by “mysqld” process:

lsof -p `pidof mysqld` |wc -l

There is a way to set system level “max open file descriptors” and view current count of “open file descriptors” at system-level;
I’m unable to recollect :(
does anyone know it?

By: Matt

Matt — Mon, 07 Jun 2010 15:06:34 +0000

I Have a files in /proc//fd which should be in a different pid fd folder! File Descriptor Leak! Closed files from another process are duplicating themselves (random number of duplicate content 5-75 times) into another process’s fd folder! Has anybody seen this before. Solaris 10.

By: apoc

apoc — Mon, 22 Feb 2010 08:26:25 +0000

you can combine lsof with pidof:

lsof -p `pidof ruby`

By: kunal

kunal — Wed, 18 Feb 2009 08:56:33 +0000

Can’t we use lsof | wc -l for the same

By: Julien

Julien — Wed, 04 Feb 2009 22:12:52 +0000

Thank you. I had a daemon that stopped functioning correctly six hours after I started it. Turns out, I had a file descriptor leak. It had never even crossed my mind until I put 2 and 2 together. This confirmed it. It’s all fixed now, thanks to you!

By: Jimi

Jimi — Tue, 03 Feb 2009 19:04:47 +0000

Thanks man, this was really useful.

By: Bogdan

Bogdan — Fri, 28 Mar 2008 16:00:54 +0000

thx, that was really useful!quick question: anybody has an idea why the value displayed by ‘lsof -p {procid} | wc -l’ is different to that of ‘ls -l /proc/{procid}/fd | wc -l’. lsof is usually higher…?

By: raj

raj — Tue, 21 Aug 2007 20:35:35 +0000

hey thanks for quick n dirty procfs tutorial :)