Re: How to increat [sic.] max open files?

Andrew E. Mileski (
Fri, 3 Jan 1997 14:42:38 -0500 (EST)

> Okay! Now, how many FDs should a process be allowed to have? This has to
> be defined by a rule, not a good rule, not a bad rule, but simply a rule!
> I think we need ANSI or POSIX or some such "committee" to make such a rule.
> ... even though I hate committees.

I am thoroughly entrenched in my belief that it doesn't need to be
changed, but instead the applications should be changed.

But, there seems to be a demand for AT LEAST 1024. I've seen people
wanting up to 2048, but not as many. I've seen very few requests for
up to 4096. I've only seen one request for anything higher.

With this in mind...

I'd go with 4096 file descriptors as a standard amount.

WARNING! This means a FD_SET is 512 bytes, and having 6 copies on the
kernel stack for select() will consume 3k of the 4k. The kernel stack
allocation must be increased.

Andrew E. Mileski
Linux Plug-and-Play Kernel Project
XFree86 Matrox Team