Linux swap with dphys-swapfile

Mon, 20 Apr 2020 10:29:10 +0000

This is a solution for a #RaspberryPi, some #VPS without swap of some machine setup without swap where you need swap for something without wanting to fiddle with the drive partitions or so.

This is a quick and dirty “short manual” for #Debian based #Systemd environments (such as #Ubuntu, #Mint or #Raspbian).

First run this:

cat > dphys-swap.sh << EOF
#!/bin/bash
#~/up
apt-get install dphys-swapfile
echo "CONF_SWAPSIZE=2048"|tee -a /etc/dphys-swapfile
dphys-swapfile setup
dphys-swapfile swapon
systemctl restart dphys-swapfile.service
systemctl status dphys-swapfile.service
free -h
EOF

This will just create a short #bash #script with the needed commands to run to get #dphys setup and running. Please alter the number 2048 to your need, it is the size of the swap memory that will be setup. The size of the swap should most likely by equal to the real memory installed, sometimes twice the size seems to be a good choice too.

rename

Mon, 29 Apr 2019 20:06:29 +0000

… is an easy to use and powerful tool, it can be used to replace part of file name (string1) with some other string. Something one can also do with some “sed” hack, but this tool is much easier to use, especially for beginners.

You can get all information needed from “rename –help” (here from Linux Mint):

rename --help
Usage:
    rename [ -h|-m|-V ] [ -v ] [ -n ] [ -f ] [ -e|-E perlexpr]*|perlexpr
    [ files ]

Options:
    -v, -verbose
            Verbose: print names of files successfully renamed.

    -n, -nono
            No action: print names of files to be renamed, but don't rename.

    -f, -force
            Over write: allow existing files to be over-written.

    -h, -help
            Help: print SYNOPSIS and OPTIONS.

    -m, -man
            Manual: print manual page.

    -V, -version
            Version: show version number.

    -e      Expression: code to act on files name.

            May be repeated to build up code (like "perl -e"). If no -e, the
            first argument is used as code.

    -E      Statement: code to act on files name, as -e but terminated by
            ';'.

I did use this tool rename some files that contained the string “www”, which I had to replace with “web”, lets say there were files named like this:

Ubuntu on tech.notes

Linux swap with dphys-swapfile

rename