limit command

[Tarek]

A user asked me to modify some parameters of the limit command. I haven't understood yet what kind of parameters are, but they seem to be concerning shell and not kernel..is it right?? I saw that i can configure them in my .cshrc. However i tried to configure the datasize, which actually is set to 2015464 to unlimited but it doesn't work. Why? On another hp with same OS (hpux11) there's set (i think by default), datasize to unlimited.
This is the entry i have now:
cputime unlimited
filesize unlimited
datasize 2015464 KB
stacksize 81612 KB
coredumpsize 2097151 KB
descriptors 200 files
memoryuse unlimited
Can someone explain me what parameters are this? I haven't a man of limit.
Thanks in advance
Tarek

[Sridhar Bhaskarla]

I haven't heard of any command called limit that can be used to limit the resources.

Some the of the terms you listed fall under kernel parameters, Some can be done by PRM (Process Resource Manager).

-Sri

[Sanjay_6]

Hi Tarek,

Take a look at the threads below for more info.

http://us-support2.external.hp.com/cki/bin/doc.pl/sid=73945b0c0d02e1f2f0/screen=ckiDisplayDocument?docId=200000047257288

http://us-support2.external.hp.com/cki/bin/doc.pl/sid=73945b0c0d02e1f2f0/screen=ckiDisplayDocument?docId=200000047385472

http://us-support2.external.hp.com/cki/bin/doc.pl/sid=ef13e92906bfcef50f/screen=ckiDisplayDocument?docId=200000015663097

Hope this helps.

Thanks

P.S. : the Spikes from your UPS are not a good sign. You should replace the UPS or get it rectified. That could be the cause of your problem.

[A. Clay Stephenson]

Hi:

The command you are looking for is 'ulimit'. It is a shell built-in so you need to man csh, or man sh_posix, or man ksh to see what the various settings do. There is also a ulimit system call. Man 2 ulimit for those details.

Typically, the absolute maximum limits are defined in the kernel (like maxdsiz,maxssiz,maxtsiz) these can be further limited by ulimit settings. The rule is that only a super-user can increase a ulimit value but only to the maximum the kernel allows. A regular user can only reduce a current ulimit setting.

[Santosh Nair_1]

I think the user is asking about the ulimit command...not the limit command. In any case, some of these limits can be changed dynamically if you're using the Posix Shell (/usr/bin/sh) or C-Shell (/usr/bin/csh). There are also kernel parameters associated with some of these limits, specifically:

ulimit kernel parameter
datasize maxdsiz
stacksize maxssiz
descripter maxfiles
Hope this helps.

-Santosh

[Sanjay_6]

Hi Tarek,

Sorry abt the earliaer posting. It got posted at the wrong place. It was an answer to some other question.

Sorry abt that.

[Sanjay_6]

Hi Tarek,

Here is a thread for you to look at. Sorry abt the earlier wrong postings.

http://docs.hp.com/cgi-bin/fsearch/framedisplay?top=/hpux/onlinedocs/B2355-90680/B2355-90680_top.html&con=/hpux/onlinedocs/B2355-90680/00/00/57-con.html&toc=/hpux/onlinedocs/B2355-90680/00/00/57-toc.html&searchterms=csh&queryid=20011029-090045

Hope this helps.

thanks

[Tarek]

I'm talking about limit not ulimit.
If i issue ulimit i have this output:
unlimited
If i issue limit, i have the output i've told you about.
Thanks all again.

[Roger Baptiste · Accepted solution]

Hi,

The limit command is used to set a limit
on the resources being used by a shell and
the processes it spawns. For instance, if
one wants to limit the size of a core file
which a user process can dump, the limit
command would be handy to do it. Similarly,
the heapsize , max number of files etc can
be configured. The command name and features vary according to the shell.

For C shell, it is the "limit" command;
For K and Bourne shell, it is called "ulimit".

A user cannot increase a limit beyond the
"hard limit" (which is set by default and
can be changed only by the superuser).

>>However i tried to configure the datasize, >>which actually is set to 2015464 to >>unlimited but it doesn't work. Why?

try using limit -h option (-h is for
hard limit).

>>On another hp with same OS (hpux11) there's >>set (i think by default), datasize to >>unlimited.

The shell must be KSH which sets unlimited
by default.

>>This is the entry i have now:
cputime unlimited ->Maximum CPU seconds per process
filesize unlimited ->Largest single file allowed; limited to the size of the filesystem

datasize 2015464 KB -> Heap size
stacksize 81612 KB -> Max stack size
coredumpsize 2097151 KB -> Ah! max coredump
descriptors 200 files -> max open files
memoryuse unlimited ->max virtual mem size
This definitions are at shell level.

Do a man on ulimit or sh to get more details.
In ksh ulimit -a will give the defined values.
Another quirk i have seen is Bourne shell
does not take "unlimited" as an value.

Man on csh and search for limit to get
the options for csh's limit.

HTH
raj

[Tarek]

Rajman,
your answer was perfect, but i still need more help. You wrote:
A user cannot increase a limit beyond the
"hard limit" (which is set by default and
can be changed only by the superuser).
Where can i change the default settings?
I tried limit -h datasize unlimited but it still didn't work. I also tried limit -h, same output.
Can you help me again or anyone else?
Thanks in advance
Tarek