Backup jobs display either of the the following warnings:
The Repository database cannot grow over 64 TB due to the JET Blue database engine limitations. Should this limit be reached while some transactions are still uncommitted, the database will be left in a dirty shutdown state with no option to recover it, as there is no more free space to commit those transactions.
To avoid such scenario, a warning and a fail-safe mechanism were hardcoded into Veeam Backup for Microsoft Office 365. The warning will appear once repository database file reaches 58TB, and the error will block any jobs from writing into such file once it reaches 60TB.
Note: Space is calculated based on the size of the database file and available space within the file. Thus, if you have a 60TB container (file) and 50TB of it marked as free space, you will receive neither warning nor error