Its backups, since it will, by design, eventually use all the spaceĪvailable. This is a trade-off between space and how long Time Machine can keep Up large amounts of backup space, for various reasons. Tendency to add more and more data to our systems over time, so if inĭoubt, get a bigger one than you think you need now.Īlso, there are some OSX features and 3rd-party applications that take Unfortunately, it's rather hard to predict, and most of us have a

A drive that's too small may only have roomįor a few weeks (or even days) of backups. To work, but that's subject to problems any time a large backup isĪnd, of course, the larger the drive, the more old backups Time If you're a light user, you might be able to get 1.5 times If youįrequently add/update lots of large files, then even 5 times may notīe enough. Sure to add the size of the data on any other drives/partitions youīut this varies greatly, depending on how you use your Mac. Time Machine needs 2 to 4 times as much space as the data it'sīacking-up (not necessarily the entire size of your internal HD). How big a drive do I need for Time Machine?Ī general 'rule of thumb' is, to keep a reasonable 'depth' of backups, I'm running MacOS 10.11.5 and the target is on a NAS so I can't format with Disk Utility.You probably want to check out this website for the most information, but here is the answer to your question, quoted from the website above: 1.

Note the size is 290 GB which is what it should be.īut whatever I do, my Mac keeps seeing the target as being too full to backup to as though it's got 'stuck' on a certain capacity and quantity free space. When I re-add it, a new 400MB sparsebundle is created which contains ist and Info.bckup files with the following data:

And it still reports as only 44 GB free meaning I can't start a new backup even though it's empty according to Terminal. Still, whenever I add the TMBackup as a source it still reports as 300 GB total size. I've also rebooted both the Time Machine target and the Mac. It still reports it as only 44 GB free when I re-add the target to Time Machine. I've tried changing the backup target size, adding and removing it and I've tried deleting the sparsebundle completely. I've given up trying to get around this and now I want to just delete it completely and start again. No matter what, it always says the same capacity and same amount of free space. Even after I delete all the backups and the sparsebundle itself. My Time Machine keeps reporting as 44 GB free of 300 GB so it can't backup.

Time machine backup mac capacity