When Time Machine attempts to backup my Mac, it fails saying there isn't enough disk space.

 

When I first select the drive, it shows the proper amount of disk space (in this case 2.2TB of FREE space) but then after Time Machine attempts a backup it says something like ZERO KB of 1.01 MB available.  So it appears that the Mac OS isn't seeing the correct disk space.

 

I've tweak several of the UNRAID settings trying to find a solution, but I'm getting nowhere.  I have about 280GB of data to backup, and there is plenty of space (over 2 TB available on the drive I've dedicated to Time Machine).

 

It's probably a simple setting, but I'm not seeing it, and I can't find anything in the forums.

 

The exact error I'm getting is "The backup disk needs 279.72 GB for the backup but only Zero KB are available. Select a larger backup disk or make the backup smaller by excluding files."

 

I have the Time Machine Volume Limit Size set to 2 Terabytes, I've also left that setting blank and get the same error.  Allocation method is set to High Water, Minimum Free Space is set to 1GB (but I've tried that set to blank as well)  I have USE Cache disk set to NO,  The volume I'm using is a reiserfs formatted volume.

 

I'm running the latest UNRAID 6.1.9, and I'm running the latest Mac OS X 10.11.5 (El Capitan).

 

I've had Time Machine working in the past, but haven't used it in over a year.

 

Thanks in advance.

 

Mike

This is an old thread, but in case someone is looking for the answer, I think I may have stumbled upon it.

 

From the Guide:

 

 

Fill-up: The fill-up allocation method simply attempts to fill each disk in order from the lowest numbered disk to the highest numbered disk. The fill-up allocation method must be used in conjunction with the minimum free space setting. Otherwise, unRAID will begin to give disk full errors and not allow any more transfers once the first disk gets close to being full.