Linux

Ʌ: Tech

Get IP of default gateway

ip r (alias for ip route), first line

NTP on systemd

timedatectl

timedatectl set-ntp true

timedatectl timesync-status

Troubleshooting

grep systemd-timesyncd /var/log/syslog | tail

Also check for the status of systemd-timesyncd.service (or restart it?)

NTP port blocked?

Use htpdate.

DD & PV w/ filesize

dd if=$image|pv -s (du -b $image|cut -f -1)|sudo dd of=$destination

Limiting CPU time of a process

i.e. not priority (via nice) but actual cpu utilization

using cpulimit:

cpulimit -l $PERCENTAGE -p $PID

Note: Unlike nice, cpulimit blocks and runs continuously!