Just wanted to make a feature request. When we see this warning message the incremental is as large as the full backup. If the free disk space is smaller than the full backup then the backup drive runs out of space and the only way to recover is to delete all the backups.
I'd like to see Veeam fix this programmatically so that it merges incrementals into the full backup until there is enough free disk space to continue.
25/09/2026 2:28:31 pm :: Disk 0 layout change detected, resetting changed block tracking for all volumes on this disk
Full sized backup after disk layout change is by design.
We can't interfere with backups chains as it would break the retention policy and I think retention won't make room for that, because the agent transforms the chain only after it has created the new restore point. That's why we recommend keeping room for at least one extra full on the target.
I may only recommend something like that: If the layout change is planned for any reason, shorten the retention period a few runs ahead of it and set it back afterwards.