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· · zu lesen

How to add a swap drive to your system, in this case I did this for a virtual machine (qemu) running Arch Linux.

See at the bottom for information about the virtual drive for qemu.

List current available to system disks:

sudo blkid

List all disks:

sudo lsblk

Format as swap:

sudo mkswap /dev/vdb

gives back the UUID

Now the new swap disk will be shown when executing this again:

sudo blkid

(also give the UUID)

Take the UUID from above and add an entry in /etc/fstab like this:

echo "UUID=56445300-90f5-40b4-860b-99037d0e8aad none swap sw 0 0" |sudo tee -a /etc/fstab

Actiate available swap disks, ie. from fstab or on GPT volume. 

sudo swapon -a

Check the swap is available now:

sudo swapon --show

The qemu image I created as „raw“, VirtIO and set the cache mode to „writeback“, this should be fine for swap while being fast too. See explanation here and here.

I also looked at this information about how to add a swap disk.

As always, give me your feedback, I will add information that can help in the future.

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· · zu lesen

… 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:

www.example.com-97126.ccd
www.example.com-54852.ccd
www.example.com-87430.ccd
www.example.com-75413.ccd

For Ubuntu, maybe also Debian, based systems I use the following command to rename all above files:

rename -e 's/www/web/' *.ccd

After this the files are now called
web.example.com-….
….

The only problem is, the syntax varies from one Linux distribution to another, so check the syntax before you use rename.

For Arch Linux I found that something like this would work:

rename www web *.ccd

The expression „*.ccd“ defines which files to act on, so this will act on all files that match „*.ccd*, in the example above you could also use „www.example.com-*.ccd“ or something similar.

Main thing I wanted to get out there is, there is an easy tool to batch rename files instead of some complex if-for bash code. Which I tried to use before but failed at.