@topspin said in WTF Bites:
@Gurth It's relatively new, but I guess I should check.
But the OS didn't complain that it couldn't write, or anything like that. It currently shows 332.5GB in use for that 35% backup. Scaling that up, it thinks it needs 950 GB to back up a 512 GB SSD, even assuming all of that SSD is in use with local snapshots and nothing is excluded.
I formatted the whole thing as a single volume, then checked with f3. All good, could write and read the full capacity.
So I split it into partitions again, gave the Time Machine partition 350 GB, this time knowing all the previous data was definitely gone, and started again with a whole bunch of exclusions configured:
(I saw that the last one had stuff from /System/Library backed up, even though /System was excluded, so I added that too. )
Well, it failed again. 331.5 GB written, 18.5 GB left available.
Who wants to take bets that if I give it the whole 512 GB, same size as the internall SSD, it still won't be enough?