Cheatsheet Pages / systemd Cheatsheet
How to find where boot time went — systemd-analyze blame and critical-chain
Boot feels slow and guessing is not working — blame shows per-unit times, critical-chain shows the chain that actually gated the boot.
Most management commands need sudo, and systemctl only works on a system actually booted with systemd — inside containers it fails with “System has not been booted with systemd as init system”. Every command was checked against systemd 255, and the example units pass systemd-analyze verify.
systemd-analyze # total startup time (firmware / loader / kernel / userspace)
systemd-analyze blame # every unit, slowest first — start optimising at the top
systemd-analyze critical-chain # the chain that actually gated boot (blame alone misleads:
# a slow unit off the critical path costs you nothing)