Unix and Linux Stack Exchange
Unix and Linux Stack Exchange

Questions tagged [resources]

92 questions
63
votes
2 answers

Running dd. Why resource is busy?

I just formatted microSD card, and would like to run a dd command. Unfortunately dd command fails: $ sudo dd bs=1m if=2016-02-26-raspbian-jessie-lite.img of=/dev/rdisk2 dd: /dev/rdisk2: Resource busy $ Everyone on the internet says I need to…
oldhomemovie
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5 answers

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.
user5554
30
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1 answer

How to use cgroups to limit all processes except whitelist to a single CPU?

There is a guide to cgroups from Red Hat which is maybe sort of kind of helpful (but doesn't answer this question). I know how to limit a specific process to a specific CPU, during the command to start that process, by: First, putting the following*…
Wildcard
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29
votes
1 answer

Why does it take up to several minutes to clean a listening TCP port after a program dies?

If I kill a program that is listening on a TCP port, it takes up to several minutes until the port is reclaimed by the system and usable again. I've seen several Q/A mentioning this phenomenon, but without an explanation. Why does that happen, why…
Petr
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24
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6 answers

Is there a way to limit overall CPU consumption?

My laptop (an HP with an i3 chip) overheats like crazy every time I run a resource heavy process (like a large compilation, extracting large tarballs or ... playing Flash). I am currently looking into some cooling solutions but got the idea of…
rahmu
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24
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3 answers

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 VIRT in the likes of top. More on the topic e.g.…
jpe
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22
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2 answers

What do top's %MEM and VSZ mean?

I'm working on an embedded Linux system (128MB RAM) without any swap partition. Below is its top output: Mem: 37824K used, 88564K free, 0K shrd, 0K buff, 23468K cached CPU: 0% usr 0% sys 0% nic 60% idle 0% io 38% irq 0% sirq Load…
djf
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21
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3 answers

Resource usage using pipe and here string

We can get the same result using the following two in bash, echo 'foo' | cat and cat <<< 'foo' My question is what are the difference between these two as far as the resources used are concerned and which one is better ? My thought is that while…
utlamn
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19
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3 answers

ulimit & rlimit in Linux, are they the same thing?

I see people use the terms ulimit & rlimit interchangeably, can I say they are referring to the same thing?
Ryan
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17
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1 answer

Is it wrong to think of "memfd"s as accounted "to the process that owns the file"?

https://dvdhrm.wordpress.com/2014/06/10/memfd_create2/ Theoretically, you could achieve [memfd_create()] behavior without introducing new syscalls, like this: int fd = open("/tmp", O_RDWR | O_TMPFILE | O_EXCL, S_IRWXU); (Note, to more portably…
sourcejedi
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16
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2 answers

How to prevent fork bomb?

To prevent fork bomb I followed this http://www.linuxhowtos.org/Tips%20and%20Tricks/ulimit.htm ulimit -a reflects the new settings but when I run (as root in bash) :(){ :|:&};: the VM still goes on max CPU+RAM and system will freeze. How to ensure…
user44441
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14
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1 answer

Does 'ulimit -m' not work on (modern) Linux?

This article claims that the -m flag to ulimit does nothing in modern Linux. I can find nothing else to corroborate this claim. Is it accurate? You may try to limit the memory usage of a process by setting the maximum resident set size (ulimit…
Flimzy
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14
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3 answers

Is there a way to find all X resources an application uses?

I'm looking for a way to automatically list all X resources that are used in an application. To give you an example, for xterm I'd expect a list similar to the following but with all the resources that are used by xterm. background foreground …
bbuser
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11
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4 answers

Where can I find the historical source code of the Linux sources

I want to do research on the evolution of Linux. Therefore it would be nice if I could download the sources of Linux at several moments in time (from 1991 till now). Is there a site where one can find those sources? Similar sites for other Unix…
Willem Van Onsem
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11
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2 answers

How to check, which limit was exceeded? (Process terminated because of ulimit. )

Let's assume process runs in ulimited environment : ( ulimit ... -v ... -t ... -x 0 ... ./program ) Program is terminated. There might be many reasons : memory/time/file limit exceeded ; just simple segfault ; or even normal termination with…
Grzegorz Wierzowiecki
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