topic Re: maxfiles in Operating System - HP-UX

maxfiles

Sonny_8 — Mon, 13 Jan 2003 10:59:39 GMT

Dear all
If I set the maxfiles parameter to 4096 from kernel.
It will have any problem in the future.
What kind of probem will have?
What the recommend values?
Any idea or thought would be appreciated

Regards
Sonny

Re: maxfiles

Stefan Farrelly — Mon, 13 Jan 2003 11:05:44 GMT

NO, you wont have any problems from running maxfiles at 4096 or higher. All is does it use a tiny amount of system memory for the table. We run ours at anywhere from 4096 to several thousand and have never had a problem.

Re: maxfiles

Armin Feller — Mon, 13 Jan 2003 11:08:14 GMT

Hi,

if patch PHNE_27217 is already installed you shouldn't get problems with setting 'maxfiles' higher up then 2048. But you should also increase 'maxfile_lim' to 4096.

Regards ...
Armin

Re: maxfiles

Ravi_8 — Mon, 13 Jan 2003 11:11:49 GMT

Hi, sonny

you will not be having any problem if you set the maxfile to 4096.

recommended value is based on application you are running. for oracle/db2 i set the maxfile to 4096, happily running

Re: maxfiles

Vicente Sanchez_3 — Mon, 13 Jan 2003 11:17:35 GMT

Hi Sonny,

No problem detected. We have the value of 63498.

Regards, Vicente.

Re: maxfiles

Bill Hassell — Mon, 13 Jan 2003 12:46:26 GMT

maxfiles (and maxfiles_lim) are runaway program fences. That is, they simply prevent bad programs from using all the open file descriptors. If you have programmers that insist on opening thousands of files at the same time in a single program, then you'll have to decide whether to let those programs run on your system (by increasing maxfiles and maxfile_lim) or asking them to rewrite their program(s).

maxfiles is a per-program limit for the maximum number of files that can be opened at one time. This is a soft limit which can be changed using the setrlimit system call or with the HP-UX POSIX shell using ulimit -n (man sh-posix). Once ulimit has been set in the shell (see ulimit -a) for file descriptors, all subsequent processes started from that shell will inherit the new value for maxfiles. ulimit defaults to a new hard limit. Use the -S option to change up or down.

maxfiles is best left at 60 to 100 as the default value (put it into /etc/profile and /etc/csh.login) and allow specific processes to run at a higher limit with a start script. maxfiles cannot be increased beyond the kernel's hard limit of maxfiles_lim.

NOTE: If you have a dozen processes that all need 5,000 files opened at the same time, then the kernel parameter nfile must be increased by 60,000 to accomodate all the open files. nfile is for every file descriptor, not just unique files.

Re: maxfiles

Sonny_8 — Tue, 14 Jan 2003 03:06:40 GMT

thanks all

Re: maxfiles

Sritharan — Tue, 14 Jan 2003 03:45:47 GMT

Hi friends,

sorry for posting it here...

I like to know more about the configureable parameter (i'm using hpux 11.11)
is there any docs..
our setting in database server(informix9.3)
maxfiles 200
maxfiles limit 4096

user accessing the database is around 800 - 1000 per minute.

do I have to add more maxfiles ???

Thanks and sorry again
Sri

Re: maxfiles

Patrick Wallek — Tue, 14 Jan 2003 04:12:15 GMT

Sri,

Check o ut these 2 docs for 11i (11.11):

Tunable Kernel Parameters:
http://docs.hp.com/hpux/onlinedocs/TKP-90202/TKP-90202.html

Dynamically tunable kernel parameters (note that this is a PDF file):
http://docs.hp.com/hpux/onlinedocs/os/11i/DynTuneWP.pdf