Unboud (DNS) – listen on IPv4 only

Add to /etc/unbound/unbound.conf

server:
interface: 0.0.0.0

TMUX

split-window -h: Ctrl+b %

split-window -v: Ctrl+b ”

wrong Video codec on Opera Linux Mint

install chromium and

mv /usr/lib/x86_64-linux-gnu/opera/libffmpeg.so /usr/lib/x86_64-linux-gnu/opera/libffmpeg.so.orig
ln -s /usr/lib/chromium/libffmpeg.so /usr/lib/x86_64-linux-gnu/opera/

snapshots of UEFI libvirt-based (KVM) virtual machines

Shut down VM and then

Listing
qemu-img snapshot -l <file>.qcow2

Create
qemu-img snapshot -c <snap-name> <file>.qcow2

Revert to 
qemu-img snapshot -a <snap-name> <file>.qcow2

Delete
qemu-img snapshot -d <snap-name> <file>.qcow2

USB NIC reset

lsusb 
Bus 002 Device 002: ID 8087:8000 Intel Corp. Integrated Rate Matching Hub 
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub 
Bus 001 Device 002: ID 8087:8008 Intel Corp. Integrated Rate Matching Hub 
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub 
Bus 004 Device 003: ID 0bda:8153 Realtek Semiconductor Corp. RTL8153 Gigabit Ethernet Adapter 
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub 
Bus 003 Device 003: ID 04f2:b477 Chicony Electronics Co., Ltd HP HD Webcam 
Bus 003 Device 002: ID 0424:2514 Microchip Technology, Inc. (formerly SMSC) USB 2.0 Hub 
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

then
usbreset 0bda:8153

Rsync copy

rsync -azP -e "ssh -p PORT_NUMBER" source destination

KVM Snapshot with only one disk

virsh snapshot-create-as --domain ${VM}
--name "backup-${VM}" \
--atomic \
--disk-only \
--no-metadata \
--diskspec vda,file=${SNAP}/backup-snapshot-${VM} \
--diskspec vdb,snapshot=no

Boot blocks with “Gave up waiting for suspend/resume device”

usually after swap changed
update-initramfs -u

Validate /etc/network/interfaces

ifup --no-act eth0

blank console screen after 5 min

add to /etc/default/grub
GRUB_CMDLINE_LINUX="consoleblank=300"

I was able to turn off the display of the laptop by putting this command physically on to the machine and not via SSH:

setterm –blank force