====== Linux ======

<nspages user:hanez:linux -h1 -r -textPages="" -tree>

  * [[https://www.cyberciti.biz/faq/howto-create-lage-files-with-dd-command/|Create empty large files]]
  * [[https://www.addictivetips.com/ubuntu-linux-tips/back-up-email-linux-imap-grab/|How To Back Up Email On Linux With IMAP Grab]]

===== AMDGPU =====

  * [[https://www.amd.com/de/support/kb/release-notes/amdgpu-installation|Radeon Software for Linux Installation]]
  * [[https://wiki.archlinux.org/index.php/AMDGPU|AMDGPU]]
  * [[https://wiki.archlinux.org/index.php/AMDGPU_PRO|AMDGPU PRO]]
  * [[https://math.dartmouth.edu/~sarunas/amdgpu.html|AMDGPU-PRO OpenCL with the open-source amdgpu kernel module]]

===== Useful commands =====

==== Start GUI program as different user: ====

<code>xhost +SI:localuser:testuser

su - testuser -c "export DISPLAY=:0.0 && firefox"</code>

After exit you should disable acces by running:

<code>xhost -SI:localuser:testuser</code>

Everything in one command:

<code>xhost +SI:localuser:testuser && su - testuser -c "export DISPLAY=:0.0 && firefox && exit" && xhost -SI:localuser:testuser</code>

==== Howto create and mount encrypted disk ====

=== Create: ===

<code>cryptsetup luksFormat /dev/sdb1
cryptsetup luksOpen /dev/sdb1 crypto
mkfs.ext2 /dev/mapper/crypto</code>

=== Mount: ===


<code>cryptsetup luksOpen /dev/sdb1 crypto
mount /dev/mapper/crypto /mnt/crypto</code>

=== Unmount: ===


<code>umount /dev/mapper/crypto
cryptsetup luksClose /dev/mapper/crypto</code>

=== Change Key: ===


In LUKS scheme, you have 8 "slots" for passwords or key files. First, check, which of them are used:

<code>cryptsetup luksDump /dev/sdb1 | grep BLED</code>

Then you can add, change or delete chosen keys:

<code>cryptsetup luksAddKey /dev/sdb1 (/path/to/<additionalkeyfile>)</code>

<code>cryptsetup luksChangeKey /dev/sdb1 -S 6</code>

As for deleting keys, you have 2 options:

a) delete any key that matches your entered password:

<code>cryptsetup luksRemoveKey /dev/sdb1</code>

b) delete a key in specified slot:

<code>cryptsetup luksKillSlot /dev/sdb1 6</code>