ulimit command


 
Thread Tools Search this Thread
Operating Systems Solaris ulimit command
# 1  
Old 02-12-2007
ulimit command

Hi,

I have a Sun machine 5.8 and would like to modify the ulimit parameter for numner of file descriptors.

the output of plimit <process name> is:

Code:
4100: process_name
resource              current         maximum
  time(seconds)         unlimited       unlimited 
  file(blocks)          unlimited       unlimited
  data(kbytes)          unlimited       unlimited
  stack(kbytes)         8192            unlimited
  coredump(blocks)      unlimited       unlimited
  nofiles(descriptors)  30000           30000 
  vmemory(kbytes)       unlimited       unlimited

I need to increase the number of file descriptor by 512. I will insert this command on the script:

Code:
ulimit -n 512

The script will look something like this:

Code:
#!/usr/bin/ksh -a
#
NAME=testprocess
export NAME
ulimit -n 512
exec /opt/bin/process "$@"

I haven't used this command before. Will this increase the existing size to 512 or will it reduce the nofiles to 512?

I am unable to determine the nofiles using the plimit. how would I know the current settings for nofiles? so that I can know if the "ulimit -n 512" command is correct.

Also, does it have a maximum value for that one? And also the impact on the system resources as well.

I can not test this one until I am sure since I will be doing it on a live network.

Thanks.

Last edited by inquirer; 02-12-2007 at 07:47 AM..
# 2  
Old 02-12-2007
Quote:
Originally Posted by inquirer
Hi,

I have a Sun machine 5.8 and would like to modify the ulimit parameter for numner of file descriptors.

the output of plimit <process name> is:

Code:
4100: process_name
resource              current         maximum
  time(seconds)         unlimited       unlimited 
  file(blocks)          unlimited       unlimited
  data(kbytes)          unlimited       unlimited
  stack(kbytes)         8192            unlimited
  coredump(blocks)      unlimited       unlimited
  nofiles(descriptors)  30000           30000 
  vmemory(kbytes)       unlimited       unlimited

I need to increase the number of file descriptor by 512. I will insert this command on the script:

Code:
ulimit -n 512

The script will look something like this:

Code:
#!/usr/bin/ksh -a
#
NAME=testprocess
export NAME
ulimit -n 512
exec /opt/bin/process "$@"

I haven't used this command before. Will this increase the existing size to 512 or will it reduce the nofiles to 512?

I am unable to determine the nofiles using the plimit. how would I know the current settings for nofiles? so that I can know if the "ulimit -n 512" command is correct.

Also, does it have a maximum value for that one? And also the impact on the system resources as well.

I can not test this one until I am sure since I will be doing it on a live network.

Thanks.
Remember you may need to update /etc/system for the changes you plan on making to be persistent across reboots.
# 3  
Old 02-13-2007
Error

dudes,

i need this very urgent....

i executed the command plimit <PID>... i was expecting an output either 256, 512, 1024, etc but instead the output was 30000.... this is different.

i am afraid that if a change it using "ulimit -n 512" the 30000 will become 512... which is very small. i need your opinion about this.

please help
# 4  
Old 02-13-2007
Quote:
dudes,

i need this very urgent....

i executed the command plimit <PID>... i was expecting an output either 256, 512, 1024, etc but instead the output was 30000.... this is different.

i am afraid that if a change it using "ulimit -n 512" the 30000 will become 512... which is very small. i need your opinion about this.

please help
It will not increase, but rather will set it to 512, just tested that. For the max value of nofiles, i really dont know Smilie but you can always try "ulimit -n 30512" and let us know the result ...
# 5  
Old 02-13-2007
hmmm... the problem is that when i tried to check the other related settings like "plimit <PID>"

it tells me that it was already at its maximum value:

Code:
                  current          maximum
nofiles         30000            30000

i also tried to look at /etc/system and has the following value:

Code:
set rlim_fd_max=1024
set rlim_fd_cur=256

the question is can i still be able to set the nofiles value greater than 30000? is the setting at the /etc/system not related to the setting in the pfiles/plimit command?
# 6  
Old 02-13-2007
I see, you still can change it (nofiles) system wide with root, i did mine just like that
Code:
ulimit -a ; uname -a
time(seconds)        unlimited
file(blocks)         unlimited
data(kbytes)         unlimited
stack(kbytes)        8192
coredump(blocks)     unlimited
nofiles(descriptors) 50000
vmemory(kbytes)      unlimited
SunOS ---- 5.8 Generic_xxxxxx-xx sun4u sparc SUNW,Sun-Fire-480R

but if the limit is still 30000 on yours then I suspect some login profile is calling ulimit to fix it at 30000 if so just make the necessary change
# 7  
Old 02-13-2007
i need to change only a particular file....

example, scriptA has the following plimit <PID of scriptA>value:

Code:
               current           maximum
nofiles       30000            30000

you mean if i insert the following:

Code:
#!/usr/bin/ksh -a
#
NAME=testprocess
export NAME
ulimit -n 40000
exec /opt/bin/process "$@"

it will not give any error? what is the sample output of the plimit <PID of scriptA> value afterwards?

thanks for the help.
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. Red Hat

Ulimit -c unlimited

I was trying to generate core dump of a process.But it is not generated. While digging up the issue I found that Core File Size is set to 0. I set it with #ulimit -c unlimited.After that I found the core file size is set to 0 (ulimit -a).I exit that session and again logged in.But found the core... (12 Replies)
Discussion started by: Anjan Ganguly
12 Replies

2. Red Hat

ulimit command

In Linux, What is the difference between using this command ulimit -c `ulimit -cH` and ulimit -c `ulimit -Hc` ? Thanks (4 Replies)
Discussion started by: mrn6430
4 Replies

3. Linux

ulimit -n

Hi im a complete noob to shell commands but here is my problem i have a dedicated server i7 with 24 gig ram i have whm/cpanel on it now ive added a minecraft system to root but i cannot set the server to more than 512mb memory i was told its because the memory is being blocked and was told to... (7 Replies)
Discussion started by: gazzac
7 Replies

4. Solaris

ulimit

Hello, could you help me please? I write in command line: "ulimit 500" -> i've set the max size of 512-bytes blocks that i can write in one file. But when after it i use ulimit.3c in my program: "ulimit(UL_GETFSIZE);" the result turns out 1000. Why is it so? They always differ so that one is... (2 Replies)
Discussion started by: Zhenya_
2 Replies

5. HP-UX

ulimit Command Problem???

Hi, I have changed the ulimit for the user dsadm on one of my server. Its only changed IF i su to dsadm from root, but its not changing if i ssh to dsadm. i want to change the data(kbytes)to unlimited. i edit the /etc/profile and .profile of dsadm user by set this my OS 11.31 ulimit -d... (1 Reply)
Discussion started by: mousa55
1 Replies

6. Solaris

ulimit

how do i check the ulimit set on my server.. ca i know whats the command ?? thanks in advance .. (5 Replies)
Discussion started by: expert
5 Replies

7. UNIX for Advanced & Expert Users

ulimit

hi what is the difference between file and data? if file is unlimited, does that mean we can have a file as big as we like? thanks. file(blocks) unlimited data(kbytes) 1048576 (6 Replies)
Discussion started by: JamesByars
6 Replies

8. Solaris

ulimit

Hi, I need to increase the open files on my server to run a test. Usually what I do is: ulimit -n 5000 My questions are: 1] I want to set this parameter once and for all. What is the right parameter to set in /etc/system: rlim_fd_max or rlim_fd_cur? 2] How to make sure that this... (1 Reply)
Discussion started by: melanie_pfefer
1 Replies

9. UNIX for Dummies Questions & Answers

ulimit

Hi, system aix 4.3 when I execute umilit i get result "unlimited". why cant i ftp or extract from media filesize over 2gig.... e.g FS /test/testy is large file enabled. any help will be greatly appreciated. thnx (3 Replies)
Discussion started by: Student37
3 Replies

10. UNIX for Dummies Questions & Answers

ulimit -d

All I am trying to do ulimit -d unlimited and I get "sh: ulimit: The specified value exceeds the user's allowable limit." Can someone please help me understand, how to change this! Thanks (1 Reply)
Discussion started by: adadevil
1 Replies
Login or Register to Ask a Question

Featured Tech Videos