$ sudo mkdir -p /var/log/journal
$ grep -v '^#' /etc/systemd/journald.conf 
[Journal]
Storage=persistent
SystemMaxUse=300M
$ sudo systemctl restart systemd-journald.service

$ LANG=C sudo journalctl --list-boots
Failed to determine boots: No data available
$ sudo journalctl --verify
File corruption detected at /var/log/journal/c56cd17c662e3fc8c875401c5a259b37/system@0005f368d2135b48-c23b051fd742a581.journal~:25efd0 (of 838860
8 bytes, 29%).
FAIL: /var/log/journal/c56cd17c662e3fc8c875401c5a259b37/system@0005f368d2135b48-c23b051fd742a581.journal~ (Message invalide)
$ # remove corrupted files
$ sudo rm /var/log/journal/c56cd17c662e3fc8c875401c5a259b37/system@0005f368d2135b48-c23b051fd742a581.journal~

  [root@testserver ~]# isoinfo -d -i /dev/cdrom | grep -i -E 'block size|volume size'
  Logical block size is: 2048
  Volume size is: 327867
  [root@testserver ~]# dd if=/dev/cdrom of=test.iso bs=<block size from above> count=<volume size from above> status=progress

- Sources :

1. https://www.thomas-krenn.com/en/wiki/Create_an_ISO_Image_from_a_source_CD_or_DVD_under_Linux
2. https://lecrabeinfo.net/creer-une-image-iso-dun-disque-cd-dvd-sur-linux.html

$ ps2pdf -dPDFSETTINGS=/ebook input.pdf output.pdf

Les autres alternatives de l'option -dPDFSETTINGS sont /prepress et /printer.

Ces options donnent une conversion de meilleure qualité mais de poids supérieure.

$ convert logo_elosys.png -resize  128x128 logo.png

$ convert -resize x48 -gravity center logo.png -flatten -colors 256 -background transparent favicon.ico

$ GIT_SSH_COMMAND='ssh -i id_rsa' git push origin master

$ python3 -m pip install --user ansible
$ python3 -m pip install --user argcomplete
$ activate-global-python-argcomplete --user

$ dd if=debian.iso of=/dev/sdb bs=4M

Ajouter PubkeyAcceptedKeyTypes +ssh-rsa dans ~/.ssh/config

Ou ssh-keygen -t ed25519

Ref: SSH-RSA key rejected with message "no mutual signature algorithm"

Configuré en maître-esclave, le serveur DNS Bind9 utilise un transfert dynamique des zones.

La modification des zones sur le maître n'est pas répercutée sur le slave si les commande suivantes ne sont pas exécutées:

$ sudo rndc freeze
$ sudo rndc thaw

$ sudo journalctl -f -u bind9

This is a quick guide to mounting a qcow2 disk images on your host server. This is useful to reset passwords, edit files, or recover something without the virtual machine running.¹⁾

Step 1 - Enable NBD on the Host

$ modprobe nbd max_part=8

Step 2 - Connect the QCOW2 as network block device

$ qemu-nbd --connect=/dev/nbd0 /var/lib/vz/images/100/vm-100-disk-1.qcow2

Step 3 - Find The Virtual Machine Partitions

$ fdisk /dev/nbd0 -l

Step 4 - Mount the partition from the VM

$ mount /dev/nbd0p1 /mnt/somepoint/

Step 5 - After you're done, unmount and disconnect

$ umount /mnt/somepoint/
$ qemu-nbd --disconnect /dev/nbd0
$ rmmod nbd

$ docker network create \
       --driver=bridge \
       --subnet=10.5.0.0/16 app_net \
       --opt com.docker.network.bridge.name=app_net