Linux shell commands

Here are some useful Linux CLI commands, I will do more good examples in the future. For Germans: #maleben

Remove duplicated empty lines of a text file:

cat -s file.txt

Find and display the Windows OEM license keys in BIOS:

strings /sys/firmware/acpi/tables/MSDM | grep ".*-.*-.*-.*-.*"

Copy file between two hosts directly without third one:

scp -3 host1:/src.file host2:/dst.file

Prepend all lines with timestamp:

ls -la | ts '[%Y-%m-%d %H:%M:%S]'

Resize QEMU disk image:

qemu-img resize image.qcow2 +10G

Rescan disk size without restart:

echo 1 > /sys/block/sda/device/rescan

Reload udev rules without reboot:

udevadm control --reload-rules && udevadm trigger

Reset an USB device via software:

usb_modeswitch -v 3911 -p 7000 -R

Rotate an PDF clockwise:

pdftk input.pdf cat 1-endeast output output.pdf

Replace something in a file inplace:

sed -i 's/ONE/TWO/g' file.txt

Show SW/HW information of a host:


Display a ‘show’ like the do it in hacker movies:


List all block devices (disks), but no loop type:

lsblk -e 7

Convert a filesystem to xfs without dump/restore:

fstransform /dev/sda2 xfs

Show amount of dirty (unwritten) disk cache memory:

grep Dirty /proc/meminfo

List all network interfaces:

lshw -c network -businfo

Show the IPMI/IDRAC/ILO IP address:

ipmitool lan print | grep "^IP Address *:"

Re-read the partition table:

partprobe /dev/sda

Resize a partition:






Disable cloud-init:

touch /etc/cloud/cloud-init.disabled


echo 'GRUB_CMDLINE_LINUX="cloud-init=disabled"' >> /etc/default/grub
grub-mkconfig -o /boot/efi/EFI/ubuntu/grub.cfg


echo "DefaultEnvironment=KERNEL_CMDLINE=cloud-init=disabled" >> /etc/systemd/system.conf

Show disk space usage:

ncdu /home

Set all relevant megacli options:

megacli -AdpSetProp -NCQEnbl -aALL -NoLog
megacli -AdpAutoRbld -Enbl -aALL -NoLog
megacli -LDSetProp -CachedBadBBU -Immediate -Lall -aAll -NoLog
megacli -LDSetProp -Cached -Immediate -Lall -aAll -NoLog
megacli -LDSetProp -EnDskCache -Immediate -Lall -aAll -NoLog
megacli -LDSetProp -WB -Immediate -LAll -aAll -NoLog
megacli -LDSetProp -ForcedWB -Immediate -Lall -aAll -NoLog
megacli -LDSetProp -NORA -Immediate -Lall -aAll -NoLog
megacli -AdpSetProp BgiRate 90 -aAll -NoLog
megacli -AdpSetProp RebuildRate 90 -aAll -NoLog

-or- (for slower init/rebuild, but longer)

megacli -AdpSetProp BgiRate 20 -aAll -NoLog
megacli -AdpSetProp RebuildRate 20 -aAll -NoLog

Last updated on 2024:06:29 at 23:25 UTC

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