Comment 8 for bug 1506139

> This time, sda2 has survived as a valid and operating luks partition.

Then the journal won't show the bits where it destroys it (but it's still useful for comparison). I'd like to see a journal when it does destroy the device. One way would be to just keep rebooting until that happens.

However, there might be a faster and also more useful way. First, stop only the swap partition and luks device:

   sudo systemctl stop systemd-cryptsetup@sda2_crypt.service

Now /dev/mapper/ should not have sda2_crypt any more, just sda3_crypt (for the root partition). Then you can run the commands in /run/systemd/generator/systemd-cryptsetup@sda2_crypt.service manually with extra debugging:

   sudo SYSTEMD_LOG_LEVEL=debug /lib/systemd/systemd-cryptsetup attach sda2_crypt /dev/sda2 none luks,swap,discard
   (enter passphrase)
   sudo /lib/systemd/systemd-cryptsetup detach sda2_crypt
   # now check if the signature is still correct:
   sudo blkid -p /dev/sda2

You can try running this several times until it destroys your partition (FTR, I ran it successfully some 20 times). Does that reproduce the bug for you? If so, please copy&paste the output from the command cycle that did the destruction. If not, then I guess it's something else in the boot process, and then please reboot until it happens and attach the journal output from this boot.

Thanks!

> Furthermore, I have another problem: When doing a regular boot, but boot process hangs after systemd listed the names of several services

Please file a separate bug report about that. /usr/share/doc/systemd/README.Debian.gz describes how to debug such shutdown hangs. In particular, boot with enabling the debug shell, and when it hangs switch to it and check for running services and also save the journal. Thanks!