/dev/shm (shared memory) on linux

Posted by Kirzilla on Server Fault See other posts from Server Fault or by Kirzilla
Published on 2010-04-21T11:08:04Z Indexed on 2010/04/21 11:14 UTC
Read the original article Hit count: 235

Filed under:

linux

|

unix

|

memory-usage

Hello,

Let's imagine that we have 8Gb of RAM on server. I'm mounting /dev/shm with 4Gb on board.

mount -o remount,size=4G /dev/shm

Will this memory be strictly reserved for shared memory or if /dev/shm is empty this memory could be used by regular applications (web server, php etc.)?

PS:Sorry for my English.

I'm asking it because I've just checked df -h and found tmpfs 6.0G 0 6.0G 0% /dev/shm on 8Gb RAM sever. I don't know who made this setup, but it seems to me awful.

Thank you!

© Server Fault or respective owner

Related posts about linux

apt-get install and update fail

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I've got a problem with apt-get update and apt-get install ... commands . every time update or installing fails and errors are : Get:1 http://dl.google.com stable Release.gpg [198B] Ign http://dl.google.com/linux/chrome/deb/ stable/main Translation-en_US Get:2 http://dl… >>> More
kernel module compiling error

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
sh@ubuntu:/home/ccpp/helloworld$ make gcc-4.6 -O2 -DMODULE -D_KERNEL_ -W -Wall -Wstrict-prototypes -Wmissing-prototypes -isystem /lib/modules/`uname -r`/build/include -c -o hello-1.o hello-1.c hello-1.c:4:0: warning: "MODULE" redefined [enabled by default] <command-line>:0:0: note: this is… >>> More
Build-Essentials installation failing

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I am having trouble accessing the several critical header files that show to be a part of the build process. The "Ubuntu Software Center" shows "Build Essentials" as installed: Next I did the following two commands, which did not improve the problem: ~$ sudo apt-get install build-essential [sudo]… >>> More
Updating Debian kernel

as seen on Super User - Search for 'Super User'
I'm trying to update my Debian machine to 2.6.32-46 (which is the new stable). However, after doing apt-get update my apt-cache search linux-image shows me: linux-headers-2.6.32-5-486 - Header files for Linux 2.6.32-5-486 linux-headers-2.6.32-5-686-bigmem - Header files for Linux 2.6.32-5-686-bigmem linux-headers-2… >>> More
Serial connection over a single USB cable (Windows to linux, or linux to linux)

as seen on Server Fault - Search for 'Server Fault'
I'm helping out with a project for an embedded device that only has USB and no serial. This device is running Linux. These days, when we need to connect to a serial port on a device we typically use a USB to serial adapter (on something like a phone system or a load balancing device, etc). I would… >>> More

Related posts about unix

polkit: disable all users except those in group wheel?

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
Is it possible to do the following using 1 polkit .pkla file? Disable all users except those in the wheel group from using polkit. The users in the wheel group will need to provide the root password when using polkit. /etc/polkit-1/localauthority/50-local.d/wheel-only.pkla [disable all users… >>> More
How to find other end of unix socket connection?

as seen on Server Fault - Search for 'Server Fault'
I have a process (dbus-daemon) which has many open connection over UNIX sockets. One of these connections is fd #36: =$ ps uw -p 23284 USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND depesz 23284 0.0 0.0 24680 1772 ? Ss 15:25 0:00 /bin/dbus-daemon --fork… >>> More
Meaning of directories on Unix and Unix like systems

as seen on Server Fault - Search for 'Server Fault'
I've been using Linux for a couple of years now but I still haven't figured out what the origin or meaning of some the directory names are on Unix and Unix like systems. E.g. what does etc stand for or var? Where does the opt name come from? And while we're on the topic anyway. Can someone give a… >>> More
Easy understanding of UNIX and UNIX shell scripting!!

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi All, I am beginner to UNIX,UNIX Shell Scripting. Can you please guide me through any excellent sites for unix(which are easy to understand),some study materials(tutorials),video tutorials. Please help!! Thanks! >>> More
Is Mac OS X a licensed Unix or Unix-like clone that conforms to Unix specification?

as seen on Super User - Search for 'Super User'
Is Mac OS X developed on a licensed Unix or is it a Unix-like clone that, unlike Linux, conforms to Unix specification well enough to be registered as a Unix OS. Not until Leopard, Mac OS X did not gain the Unix certification. But in Leopard, Terminal still print: GNU bash, version 3.2.48(1)-release… >>> More