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Questions tagged [limit]

Limiting the usage of a resource (memory, disk space, CPU time, open files, network bandwidth, …) by a process or a group of processes.

37
votes
3answers
62k views

How to create a user with limited RAM usage?

So I have 4 GB RAM + 4GB swap. I want to create a user with limited ram and swap: 3 GB RAM and 1 GB swap. Is such thing possible? Is it possible to start applications with limited RAM and swap ...
65
votes
2answers
72k views

How to limit a process to one CPU core in Linux? [duplicate]

How to limit process to one cpu core ? Something similar to ulimit or cpulimit would be nice. (Just to ensure: I do NOT want to limit percentage usage or time of execution. I want to force app (with ...
139
votes
5answers
282k views

do changes in /etc/security/limits.conf require a reboot?

do changes in /etc/security/limits.conf require a reboot before taking effect? Like if I have a script that sets the following limits in /etc/security/limits.conf, does this require me to reboot ...
36
votes
3answers
89k views

Limit max connections per IP address and new connections per second with iptables

We have an Ubuntu 12.04 server with httpd on port 80 and we want to limit: the maximum connections per IP address to httpd to 10 the maximum new connections per second to httpd to 150 How can we do ...
25
votes
4answers
3k views

How to limit resource usage to save CPU+RAM for a certain process?

I have a dev server on which sshd sometimes stops working because the machine runs out of RAM. Yes we are running low on memory and upgrading is not a feasible choice right now. What I want to do is ...
8
votes
2answers
15k views

How to circumvent “Too many open files” in debian

If I want to see all relevant log files of my apache2 server at once, I use tail -f /var/kunden/logs/*log /var/kunden/logs/*log /var/log/apache2/*log |grep -v robots|grep -v favicon But since those ...
22
votes
3answers
5k views

Practical limit on the number of btrfs snapshots?

I am considering using btrfs on my data drive so that I can use snapper, or something like snapper, to take time based snapshots. I believe this will let me browse old versions of my data. This would ...
13
votes
2answers
13k views

ulimit PICKLE: “Operation not permitted” and “Command not found”

I'm trying to increase the maximum number of open files for the current user > ulimit -n 1024 I attempt to increase and fail as follows > ulimit -n 4096 bash: ulimit: open files: cannot ...
30
votes
4answers
34k views

How to Throttle per process I/O to a max limit?

I'm looking for a way to limit a processes disk io to a set speed limit. Ideally the program would work similar to this: $ limitio --pid 32423 --write-limit 1M Limiting process 32423 to 1 megabyte ...
35
votes
3answers
51k views

Creating threads fails with “Resource temporarily unavailable” with 4.3 kernel

I am running a docker server on Arch Linux (kernel 4.3.3-2) with several containers. Since my last reboot, both the docker server and random programs within the containers crash with a message about ...
14
votes
4answers
16k views

Preventing tar from using too much CPU and disk (old laptop crashes if 100%)

I want to backup 1 terabyte of data to an external disk. I am using this command: tar cf /media/MYDISK/backup.tar mydata PROBLEM: My poor laptop freezes and crashes whenever I use 100% CPU or 100% ...
36
votes
7answers
33k views

Is there a way to limit the amount of memory a particular process can use in Unix? [duplicate]

I need to test a process for memory management. I do not have the source, so I need to do all the testing from the OS side. I want to be able to say something like limitmemory 400k -p <pid> Is ...
23
votes
8answers
41k views

How to limit log file size using >>

How can I limit the size of a log file written with >> to 200MB? $ run_program >> myprogram.log
8
votes
1answer
5k views

How do you increase MAXSYMLINKS

In a python script, I am creating a bunch of symbolic links chained together. example: link1->link2->link3->.......->somefile.txt I was wondering how you can change the max number of symlinks to be ...
6
votes
1answer
2k views

How to limit speed of file copy?

I am copying huge file from NFS mount using dd: dd if=/mnt/nfs/image.img of=/dev/sda I need to limit the speed of reading from NFS. How can I achieve it? The only precondition is to use some easy ...
128
votes
3answers
169k views

Why is number of open files limited in Linux?

Right now, I know that: Find open files limit per process: ulimit -n Count all opened files by all process: lsof | wc -l Get maximum open files count allowd: cat /proc/sys/fs/file-max My question ...
31
votes
7answers
50k views

Limiting processes to not exceed more than 10% of CPU usage

I operate a Linux system which has a lot of users but sometimes an abuse occurs; where a user might run a single process that uses up more than 80% of the CPU/Memory. So is there a way to prevent ...
23
votes
1answer
14k views

Are limits.conf values applied on a per-process basis?

I'm tuning the nofile value in /etc/security/limits.conf for my oracle user and I have a question about its behavior: does nofile limit the total number of files the user can have open for all of its ...
21
votes
1answer
37k views

sudo: ulimit: command not found [duplicate]

On Ubuntu 12.04, I ran ulimit -n, it is showing 1024. I want to increase my open file limit from 1024 to 65535, so I tried the following command: sudo ulimit -n 65535 but I get the following error: ...
16
votes
3answers
6k views

Can I limit a process to a certain amount of time / CPU cycles?

We have a script which runs on our web servers, triggered by customer action, which initiates a unix process to generate some cache files. Because this process acts upon files supplied by our customer,...
9
votes
2answers
2k views

What is a canonical way to find the actual maximum argument list length?

Following ARG_MAX, maximum length of arguments for a new process it seems like ARG_MAX is wrongly (or at least ambiguously) defined on my Mac Mini 3,1 running Ubuntu 12.04: $ getconf ARG_MAX # ...
3
votes
3answers
2k views

Control Dropbox upload rate on the command line

I'm using Dropbox without the GUI in Linux. I would like to limit the upload rate, sometimes large files eats my internet bandwidth. Anyone knows how I do that?
6
votes
3answers
2k views

Externaly limiting number of CPU cores used

I need to externally limit a process/session to a certain number of cores. Are there any other possibilities than CPU affinity (I don't like the need to specify the actual cores) and cgroups (hard to ...
2
votes
2answers
1k views

Command line length limit: built-in vs executable

So per POSIX specification we have the following definition for *: Expands to the positional parameters, starting from one, initially producing one field for each positional parameter that is set....
4
votes
1answer
27k views

how to determine the max user process value?

Which value is correct?(or they are all correct, but which one will take effect?) $ cat /proc/sys/kernel/pid_max 32768 $ ulimit -a |grep processes max user processes (-u) 77301 $ cat /...
25
votes
8answers
15k views

Make disk/disk copy slower

Is there a method of slowing down the copy process on Linux? I have a big file, say 10GB, and I'd like to copy it to another directory, but I don't want to copy it with full speed. Let's say I'd like ...
30
votes
5answers
105k views

How can I increase open files limit for all processes?

I can use ulimit but I think that only affects my shell session. I want the limit increased for all processes. This is on Red Hat.
15
votes
2answers
6k views

How to limit the total resources (memory) of a process and its children

There are plenty of questions and answers about constraining the resources of a single process, e.g. RLIMIT_AS can be used to constrain the maximum memory allocated by a process that can be seen as ...
18
votes
2answers
3k views

Why is socket path length limited to a hundred chars?

On Unix systems path names have usually virtually no length limitation (well, 4096 characters on Linux)... except for socket files paths which are limited to around 100 characters (107 characters on ...
9
votes
1answer
21k views

Fixing ulimit: open files: cannot modify limit: Operation not permitted

I tested this on different GNU/Linux installations: perl -e 'while(1){open($a{$b++}, "<" ,"/dev/null") or die $b;print " $b"}' System A and D The first limit I hit is 1024. It is easily raised ...
6
votes
1answer
1k views

Limit the inode cache used by a command

I want to run a task with limits on the kernel objects that they will indirectly trigger. Note that this is not about the memory, threads, etc. used by the application, but about memory used by the ...
5
votes
1answer
2k views

Chrome too many files open / crash / Sorry Jim

When using Google Chrome I frequently get “Sorry Jim” tabs. The browser also frequently freezes and crashes. Running it from terminal emulator show a long line of Too many open files: [...:ERROR:...
6
votes
2answers
24k views

set packet rate limit via iptables

I have a packet rate limit (max. 10 per seconds) which is set by my internet provider. This is a problem if I want to use the AceStream player, because if I exceed the limit I get disconnected. How ...
5
votes
1answer
308 views

Why is the following command killing a system?

Anyone understand the following code , running in bash ? :(){ :|:& };: It seems to be a "fork" bomb on Linux.
5
votes
2answers
3k views

Does OpenBSD have a limit to the number of file descriptors?

What's the maximum number of file descriptors that a process can get on OpenBSD successfully? For example, there is an openfiles limit in login.conf(5) in OpenBSD. If I want to have as many file ...
4
votes
1answer
1k views

Is the Linux implementation of the system configuration “variable” ARG_MAX different from other system variables and is it POSIX compliant?

In the shell, as explained in this this Q&A in the context of expansion, depending on the system, the maximum length of a command's argument is initially constrained by the kernel setup. The ...
2
votes
2answers
556 views

Limiting number of processes by name

is it possible to limit number of processes for a given group or user using the process name? Eg. I'd like to groups remotes have only 5 simultaneous ssh processes that are run on my server. I don't ...
11
votes
2answers
3k views

How can I allow a user to prioritize a process to negative niceness?

I want a user to run a specific process on the system with a negative nice value. I can't simply fork the process to background as this specific program is a minecraft server and I rely on the command ...
7
votes
1answer
17k views

How to change the kernel max PID number? [duplicate]

The default PID max number is 32768. To get this information type: cat /proc/sys/kernel/pid_max 32768 or sysctl kernel.pid_max kernel.pid_max = 32768 Now, I want to change this number... but I ...
0
votes
3answers
9k views

File Size Limit

What is the maximum file size limit in rhel 32 bit OS, is there any OS limitation for the file size , if there is any limitation set then please tell me what will be for root & oaa.