I have been having a great deal of trouble with slow bootup time (30 seconds +), recently. This is not a support request, I am just describing some things I did this morning to resolve it.
Using "journalctl -b", I discovered that ntpdate was running before DNS was resolvable. Then, the bootup was waiting about 14-17 seconds before continuing. I added some workaround code into /etc/ntp.conf to allow it to sync to my local machine if it fails to connect to the ntp pool hosts. This eliminated the boot process delay that I saw in the journal, but my system still did not complete booting much faster.
Running systemd-analyze showed me that preload.service was taking almost 12 seconds. I ran a Google search on "Debian preload" and found a tip to delete file /var/lib/preload/preload.state. That did the trick! My next reboot was quite slow, but the second reboot (after preload.state had been reestablished) was the fastest I have ever seen on this system, 13.486 seconds!
Maybe this can help others or generate some conversation.
One question I still have is, why does ntpdate start before the network is accessible? Another question is, why does ntpdate start at all?
Tim
