Skip to content

🐧 Linux Cheatsheet by Harry Zijlmans

🔧 Handy Tips

🔁 Replace Strings Recursively

find ./ -type f -exec sed -i 's/old_string/new_string/g' {} \;

✍️ Insert UTF-8 Characters in Vim

i           # insert mode
Ctrl+v u2713  # ✓
Ctrl+v u00A0  # non-breaking space
Ctrl+v u2192  # →
Ctrl+v u270B  # ✋

🌉 Bridge Interface Setup

nmcli con add con-name br0 type bridge ifname br0 ip4 192.168.192.88/24 gw4 192.168.192.1
nmcli con add con-name br0-slave type bridge-slave ifname eno1 master br0
nmcli con modify br0 ipv4.dns 192.168.192.1 ipv4.dns-search example.nl

nmcli c down br0
nmcli c up br0
nmcli c up br0-slave
ping 192.168.192.1

🌀 GRUB Rescue & Booting

🔗 Rescue a non-booting GRUB

🔍 Useful GRUB Commands

grub> ls
grub> cat (hd0,1)/etc/issue
grub> set root=(hd0,1)
grub> linux /boot/vmlinuz-... root=/dev/sda1
grub> initrd /boot/initrd.img-...
grub> boot

🛠️ Permanent Fix

update-grub

🧪 Dracut Debugging

🔗 Dracut manpage

🧰 Recovery Steps

mount -o remount,rw /sysroot
vgscan --mknodes
vgchange -ay
mount --bind /sys /sysroot/sys
mount --bind /proc /sysroot/proc
mount --bind /dev /sysroot/dev
blkid
mount /dev/sdax /sysroot/boot
chroot /sysroot
dracut foobar.img

🌐 Networking with ip

ip a add 192.168.192.91/24 dev eth0
ip link set dev eth0 up
ip route add default via 192.168.192.1 dev eth0

📦 Restic Backup & Restore

🔐 Backup

restic -r /mnt/node1/restic-repo init
restic -r /mnt/node1/restic-repo backup /home/pipo/ansible --tag Ansible --tag node1

🔍 View Snapshots

restic -r /mnt/node1/restic-repo snapshots

♻️ Restore

restic -r /mnt/node1/restic-repo restore <snapshot-id> --target /tmp/pipo/

🧭 Mount Backup

restic -r /mnt/node1/restic-repo mount /tmp/restic

🧹 Remove Snapshots

restic -r /mnt/node1/restic-repo forget <snapshot-id>
restic -r /mnt/node1/restic-repo prune

🖥️ VM Management with virsh

🚀 Start VM

virsh start vm1

📂 View Disks

virsh domblklist vm1

🧠 Snapshot Management

virsh snapshot-create-as --domain vm1 --name "snap1"
virsh snapshot-list vm1
virsh snapshot-revert --domain vm1 --snapshotname snap1
virsh snapshot-delete vm1 --snapshotname snap1

🧬 External Snapshots

virsh snapshot-create-as --domain vm1 snap1 snap1-descrip --disk-only --diskspec vda,snapshot=external,file=/tmp/sn1.qcow --atomic
virsh blockcommit vm1 vda --base base.qcow2 --top /tmp/sn1.qcow --wait --verbose

🧰 Toolbox & Podman

🧪 Toolbox

toolbox list
toolbox create -c hz
toolbox run -c hz

📦 Podman

podman ps -a
podman images
podman start <container>
podman stop <container>
podman inspect <container>
podman rm <container>

📦 Snapcraft

🔗 Snapcraft

🔧 Commands

sudo snap install hugo
snap find "media player"
sudo snap refresh vlc
snap connections vlc
sudo snap remove vlc

🧾 Backup & Restore

sudo snap save
sudo snap restore <id>

🏠 HOME 🔝 Top