Time Machine on Synology keeps running out of space!

Having Time Machine backing up to Synology NAS is magic. Once on the home wifi, it just works. No having to remember to plug in a drive. Sure, backup speeds aren’t as fast as wired, but I don’t even have to think about it. That is, until the notification pops up every hour: Backup Failed, there isn’t enough space…

I have been increasing the allocation of Time Machine within my Synology over the past year or so, as Time Machine used more space. However, now I have 10Tb assigned to Time Machine. Today I watched Time Machine ‘clear space’ for an hour or so. Backup Failed, not enough space.

How can it be clearing space, then immediately not have enough space?

Recycle Bin, as Synology calls it. I had terabytes of backup data hidden in the Recycle Bin. So, as Time Machine deletes old backups, Synology is keeping them as if they were deleted files. Oops. That’s not how that was supposed to work.

I have disabled and deleted files within the Recycle Bin on the Time Machine shared folder. This has freed 7Tb of storage. Computers are backing up once again.

A very helpful feature to prevent accidental file loss on shared folders, was accidentally hoarding old backups that Time Machine was supposed to be managing and deleting. I’m pretty sure this was the cause of the problem! Time will tell if this is the permanent solution. I’ll add an update if not!