Entire 1TB SSD filled up overnight.... then was fine after hard reboot?

[Broric]

So I got a new MBP and turning it on today and it was unusable. The entire 1TB SSD was full and daisydisk reported over 800GB as "hidden space".

I hard reboot seems to have fixed it but I still don't know WTF happened.

I have mountainduck connected and thought it might have tried to sync all the external drives/servers I have mounted or something stupid but that didn't seem to be the case. Neither did anyone do anything stupid in any shared dropbox folders that auto-sync. I also have setapp installed but that didn't seem to be the culprit either.

Is this some sort of known bug? Anyone any ideas?

 

[Secubia]

Is FileVault enabled? Because I think that can happen while it's encrypting the drive.

 

[Broric]

Is FileVault enabled? Because I think that can happen while it's encrypting the drive.

Yep

Is that likely to have been a one-off?

 

[Secubia]

Yeah it only happens while it's initially encrypting, once the encryption is complete all the disk space should be released again.