Monthly Archives: December 2020

Measuring Ubuntu boot performance

Measuring boot performance in Ubunu is fairly simple. Systemd provides a tool for that.

The overall boot time for kernel and userspace is given by:


How much time each boot services takes in descending order is displayed as follows:

systemd-analyze blame

The critical chain for the default target is shown my this:

systemd-analyze critical-chain 

Those time can also be graphed as svg:

systemd-analyze plot > boot_analysis.svg

Ubuntu: clone installed packages to a new system


On the source system, do the following:

apt-get install apt-clone
apt-clone clone 

Copy \<systemname>.apt-clone.tar.gz to the new machine and run:

apt-get install apt-clone
apt-clone restore .apt-clone.tar.gz


source system:

dpkg --get-selections > ~/Package.list

target system:

apt-get update
apt-get install dselect
dselect update
dpkg --set-selections < ~/Package.list
apt-get dselect-upgrade -y