Please explain the QubesOS backup file nameing convention

Can anybody explain the QubesOS backup file naming convention, please?
I think it is qubes + vm name where the backup was created + date + SOMETHING

Could you post an example filename? I don’t have one handy.

The “SOMETHING” is probably (part of) the timestamp.

I don’t know for sure but from my observation, backup files that are created from the GUI (Qubes Manager > Backup Qubes) seem to be named as follows:

qubes-backup-yyyy-mm-ddTHHMMSS

with:

  • yyyy being the 4-digit year, e.g. 2021,
  • mm being the 2-digit month, e.g. 02,
  • dd being the 2-digit day, e.g. 13,
  • HH being the 2-digit hour, e.g. 10,
  • MM being the 2-digit minute, e.g. 35,
  • SS being the 2-digit second, e.g. 55

After all, it may be possible, that this depends on the time zone settings (regarding 12h/24h format).

The name of the qube is not stored in the backup name - that would leak information.
The date and time are taken from the system where the backup is made -
if you manually set the date back a year, the backup file will be named
using that date: plenty of scope for obfuscation here.
Backup naming uses 24hr format.

Yes, the timestamp simply follows the ISO 8601 standard.

Related PSA from xkcd.