I've done the following:

 - created a time machine backup from a mac mini with a 1TB HDD (only used about 40GB).
 - replaced the disk with a previously used, working SSD - Samsung EVO 850, 500GB.
 - time machine restore - seemed to go smooth.
 - booted up the machine.

Current state is Progress bar full with apple logo, stuck all night.


I've done a verbose boot, and could see the following errors:

    localhost com.apple.xpc.launchd[1] (com.apple.metadata.mds) <Notice>: Service only ran for 0 seconds. Pushing respawn out for 10 seconds.

Trying to load in single user mode gives the following errors:

    failed to locate mount-on path: /private/var/vm Failed to mount vm volume (2)
    failed to mount vm volume!BootCache: Root disk is an SSD, not caching

If there is any way to extract errors from the log, I could post them here.
Let me know in the comments if I can improve my question.