Commands using swapon (3)

  • create an emergency swapfile when the existing swap space is getting tight

    Create a temporary file that acts as swap space. In this example it's a 1GB file at the root of the file system. This additional capacity is added to the existing swap space. Show Sample Output


    18
    sudo dd if=/dev/zero of=/swapfile bs=1024 count=1024000;sudo mkswap /swapfile; sudo swapon /swapfile
    dcabanis · 2009-05-27 21:10:50 12
  • Clean swap area after using a memory hogging application

    When you run a memory intensive application (VirtualBox, large java application, etc) swap area is used as soon as memory becomes insufficient. After you close the program, the data in swap is not put back on memory and that decreases the responsiveness. Swapoff disables the swap area and forces system to put swap data be placed in memory. Since running without a swap area might be detrimental, swapon should be used to activate swap again. Both swapoff and swapon require root privileges.


    10
    swapoff -a ; swapon -a
    alperyilmaz · 2009-03-25 03:30:41 15
  • Add temporary swap space

    In addition to a swap partition, Linux can also use a swap file. Some programs, like g++, can use huge amounts of virtual memory, requiring the temporary creation of extra space.


    8
    dd if=/dev/zero of=/swapfile bs=1M count=64; chmod 600 /swapfile; mkswap /swapfile; swapon /swapfile
    starchox · 2009-02-16 18:36:38 855

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands

Check These Out

Create a mirror of a local folder, on a remote server
Create a exact mirror of the local folder "/root/files", on remote server 'remote_server' using SSH command (listening on port 22) (all files & folders on destination server/folder will be deleted)

Download all PDFs from an authenificated website
Replace *** with the appropiate values

Alias for lazy tmux create/reattach
If a tmux session is already running attach it, otherwise create a new one. Useful if you often forget about running tmuxes (or just don't care)

Install a LAMP server in a Debian based distribution
The execution of this command will install a LAMP server (Linux, Apache, MySQL and PHP) in a Debian based distribution. For example, in Ubuntu.

find text in a file
this will find text in the directory you specify and give you line where it appears.

locating packages held back, such as with "aptitude hold "
locating packages held back, such as with "aptitude hold "

Readd all files is missing from svn repo
When working on a big proeject with SVN, you create quite much files, for now! Can just sit here and type svn add for all of them! svn status will return a list of all of file which get ?(not add), "M"(Modified), "D"(Deleted)! This code just grep "?" flag, then add it into SVN again!

back ssh from firewalled hosts
host B (you) redirects a modem port (62220) to his local ssh. host A is a remote machine (the ones that issues the ssh cmd). once connected port 5497 is in listening mode on host B. host B just do a ssh 127.0.0.1 -p 5497 -l user and reaches the remote host'ssh. This can be used also for vnc and so on.

Get your external IP address ( 10 characters long )
Shortest url to a external IP-service, 10 characters.

execute your commands and avoid history records
$ secret_command;export HISTCONTROL= This will make "secret_command" not appear in "history" list.

Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: