Re: file descriptors??

[Craig Sanders <cas@taz.net.au>]

On Tue, 6 Jan 1998, Elie Rosenblum wrote:

> And thus spake Craig Sanders, on Wed, Jan 07, 1998 at 01:52:06AM +1100:
> > is there any debian policy on number of file descriptors compiled into the
> > kernel?  (and also in limits.h in libc6-dev - AFAIK pretty much everything
> > that uses select() will need to be recompiled if the limit is increased).
> 
> This has been sysctl configurable in the runtime kernel since at most 2.0,
> probably 1.3.
> 
> deliverator:[~]-#cd /proc/sys/kernel/
> deliverator:[/proc/sys/kernel]-#ls -l *-max *-nr
> -rw-r--r--   1 root     root            0 Jan  6 13:40 file-max
> -r--r--r--   1 root     root            0 Jan  6 13:40 file-nr
> -rw-r--r--   1 root     root            0 Jan  6 13:40 inode-max
> -r--r--r--   1 root     root            0 Jan  6 13:40 inode-nr
> deliverator:[/proc/sys/kernel]-#cat file-max inode-max
> 1024
> 4096
> deliverator:[/proc/sys/kernel]-#echo 2048>file-max; echo 8192>inode-max
> deliverator:[/proc/sys/kernel]-#cat file-max inode-max
> 2048
> 8192
> deliverator:[/proc/sys/kernel]-#

so why have there been patches to increase the number of available fd's
right up until recent kernel versions (e.g. 2.0.30)?  here's what happens on
my 2.0.32 system:

	root@siva [08:41:43] kernel# cd /proc/sys/kernel/
	root@siva [08:41:58] kernel# ls -l *-max *-nr
	-rw-r--r--   1 root     root            0 Jan  7 08:40 file-max
	-r--r--r--   1 root     root            0 Jan  7 08:40 file-nr
	-rw-r--r--   1 root     root            0 Jan  7 08:40 inode-max
	-r--r--r--   1 root     root            0 Jan  7 08:40 inode-nr
	root@siva [08:42:34] kernel# cat file-max inode-max
	1024
	3072
	root@siva [08:42:41] kernel# echo 2048>file-max; echo 8192>inode-max
	bash: file-max: Bad file descriptor
	bash: inode-max: Bad file descriptor
	root@siva [08:42:48] kernel# cat file-max inode-max
	1024
	3072

strange. your system reports 1024 and 4096 for file-max and inode-max. 
mine reports 1024 and 3072. yours allows it to be changed. mine doesn't.
what kernel version are you running? any patches? standard
linux-x.x.x.tar.gz or a debian patched kernel-source-x.x.x.deb (many of
the debian kernels were patched with various fixes and enhancements -
maybe debian's kernel should come with the linux "big-mama" or "big-mama's
best child" patch sets)? 

anyway, here's what i'm running:

	root@siva [08:42:52] kernel# uname -a
	Linux siva.taz.net.au 2.0.32 #1 Wed Dec 3 10:31:25 EST 1997 i486 unknown


bash seems to know that 256 fd's are available per process.

	root@siva [08:47:36] kernel# ulimit -a | grep files
	open files                  256

squid too (from the cachemgr.cgi):

	File descriptor usage for squid:
			Maximum number of file descriptors:    256
			Largest file desc currently in use:     25
			Number of file desc currently in use:   25
			Available number of file descriptors:  231
			Reserved number of file descriptors:    64

craig


--
craig sanders


--
TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word "unsubscribe" to
debian-devel-request@lists.debian.org . 
Trouble?  e-mail to templin@bucknell.edu .