How do I count booting time?

Question

So I have different virtual machines in different storage types and I'm trying to do a comparison of different things. One of which is booting time. How can I achieve this?

Thanks in advance.

Answer 1

If the virtual machines are Linux-based and using systemd as init service, you can use systemd-analyze:

[computer user]# systemd-analyze 
Startup finished in 17.258s (kernel) + 5.936s (userspace) = 23.194s

With systemd-analyze blame you can even check out which service took the most time:

[computer user]# systemd-analyze blame
    4min 47.840s updatedb.service
          2.539s [e-mail]
          2.257s plymouth-start.service
          2.089s [e-mail]
          1.351s man-db.service

You can even plot the boot process in a SVG graphic:

systemd-analyze plot > plot.svg