vmunix: file: table is full --secret formula for configureing kernel?

[Ratzie]

i realize that I will need to increase my kernel parameters, but I have yet to find out a fromula to use. I get responce back that yes it (nfiles) needs to be increased.
But, how do I judge to what?

I have glance running, but not very familar with it.
glance -t shows:
System Table Available Used Utilization High(%)
--------------------------------------------------------------------------------
Proc Table (nproc) 2020 351 17 18
File Table (nfile) 4619 3780 82 83
Shared Mem Table (shmmni) 1024 12 1 1
Message Table (msgmni) 664 4 1 1
Semaphore Table (semmni) 10000 21 0 0
File Locks (nflocks) 2600 65 3 3
Pseudo Terminals (npty) 200 1 1 1
Buffer Headers (nbuf) 840 840 100 100


I read once that if you have lsof you can also judge how to set the kernel.
I was told to increase MAXUSERS since that will increase nfile.
Also to increase MAXFILES

Is there a formula, script, to run to figure out what it should be?

How to use glance and lsof to full potential?
HP 11.00 with oracle 8.1.7

[Fabio Ettore]

Hi,

it is the first time for me to hear that and I will stay on this thread to know more about this news (I refer to use lsof and glance to judge how to set the kernel).

Meanwhile surely you should increase nfile or maxusers. The most important thing is increase nfile to solve the "vmunix: file: table is full ".

Best regards,
Fabio

[Ratzie]

Yes, you are correct, I do need to increase nfiles but, increasing MAXUSERS also increases this.

Parameter: nfile
Value: (16*(NPROC+16+MAXUSERS)/10+32+2*(NPTY+NSTRPTY+NSTRTEL))
Default: (16*(NPROC+16+MAXUSERS)/10+32+2*(NPTY+NSTRPTY+NSTRTEL))


I need to figure out what I need to increase it to.

[Mel Burslan]

there is no single answer to your "what do I need to increase it to question. Unless maxusers is already a huge number, my guess would be doubling the maxusers (especially if you have some comically low number like 32 or 64) and watching the tables for the next few weeks to see the utilization. Then tweak more if necessary.

Every system has its own set of requirements depending on what it does. If I were you I would scan through the unix installation document which came with your Oracle database. Usually, they give you guidelines of how the kernel parameters needs to be set.

[Pete Randall]

As a general rule, I discard the formulas and specify a number. In this case, my nfiles is set to 114548. You have to realize that increasing these kernel parameters, even significantly, only use a little bit extra memory for the kernel data structures required to store the extra data. In today's large memory systems, this should not concern you.

My answer, then, would be to look at the actual number it is set to now and double it.


Pete

[Fabio Ettore]

Hi,

looking

File Table (nfile) 4619 3780 82 83

I would say to double or triple the value of nfile. Considerations are always about what your system does. For example I see 3780/4619, that should see even by

sar -v 5 5

In file-sz column you will find

how much in use/what is the limit of nfile

Hope this helps you.

Best regards,
Fabio

[Bill Hassell · Accepted solution]

nfile and nproc are not tricky parameters. If you run out, double or triple the value. IGNORE FORMULA VALUES. They are simplistic guesses that provide only a starting point. MAXUSERS is not used in the kernel at all, it is used in several formula values. It's much easier to run sar -v 1 to see nproc and nfile, or better yet, run Glance and see many of the values and how close they are to the limit. If nfile is 4000 and you're using 3000, replace the value with 8000 and rebuild the kernel. You could make it 25000 and never worry about it again, but you'd be wasting a bit of kernel space in RAM.

MAXFILES is special: it governs how a program is allowed to behave. It allows up to MAXFILES number of files per program. A second parameter: MAXFILES_LIM is the absolute maximum number of files open per program. Using a system call (setrlimit) or changing ulimit allows you to increase or decrease this value for your current session. But the maximum is set by MAXFILES_LIM. Some vendors insist on making MAXFILES=MAXFILES_LIM=1024 or some ridiculous number when their programs never open more a few dozen files. This is a fence for runaway programs, that's all. Most programs only open a few files at the same time.

[Ratzie]

thanks