UUIDs instead of LABELs

I remember to have already read someone experiencing this, so maybe this is a duplicate.

The issue is that by loading drives using LABEL instead of UUID it's impossible to be certain which drive will be loaded, for example when builds from different days of the same month are deployed on multiple disks attached to the computer.

Since we already use datetime UUIDs, my proposal is to replace LABELs with UUIDs wherever we use them for drive selection.

Different buildmodes (keys) can then have predictable UUIDs based on SOURCE_DATE_EPOCH.

Included in !217 (closed)

Related MR

• !217 (closed)
• !253 (closed)
• !259 (closed)