Stretch stuck on boot

[Daniel Nemenyi <daniel@pompo.co>]

Dear all,

My laptop has for the second time got stuck on boot, and a seemingly
random number of hard reboots has been necessary to get it running. This
obviously worries me. I'm running Debian Stretch with full disk
encryption and, after grub, this is what happens:

 WARNING: Failed to connect to lvmetad. Falling back to device scanning.
 Volume group "hostname-vg" not found
 Cannot process volume group hostname-vg
Please unlock sda3_crypt: # password inserted
 WARNING: Failed to connect to lvmetad. Falling back to device scanning.
 Reading all physical volumes. This may take a while...
 Found volme group "hostname-vg" using metadata type lvm2
 WARNING: Failed to connect to lvmetad. Falling back to device scanning.
 2 logical volume(s) in volume group "hostname-vg" now active.
cryptsetup (sda3_crypt): set up successfully
/dev/mapper/hostname--vg-root: clean 927829/14712832, 50294056/58823680
blocks.

At that point it gets stuck. The other time this happened the numbers
were different (lower)

When it does eventually boot, the next lines are:
[48.862647] nouveau 0000:04:00.0: bus: MMIO write of 0000807f FAULTat 100c18
[48.945694] nouveau 0000:04:00.0: bus: MMIO write of 0000807e FAULTat 100c1c
... and then normal boot.

Is this a sign of the end of my laptop or SSD or is there something I
can do?

Thanks
Daniel