Time Machine starts from scratch??

[mpts]

Hey guys,

I haven't used TM in a while, but I'm wondering why TM would always start from scratch when making backups?

I have done a full backup last week (~290GB) and today I plug my external disk into my MBP and it will simply restart the entire process ("backing up xx of 260GB") instead of simply adding the delta? Is this the way TM does backups?? Seems a bit annoying to me since it takes ages this way every time.

Thanks!

 

[mpts]

Yea, something seems to be wrong. My backup now stopped, TM saying it failed due to lack of space, which is definitely not the case.

I am creating a ~300Gb backup to an external drive that has 1TB of space. Last week I made the first TM backup. Today the second. So even if it would create two separate copies I would still have plenty of space.

The message I got from TM was: "This backup is too large for the backup disk. The backup requires 308.28 GB but only 156.60 GB are available.

Time Machine needs work space on the backup disk, in addition to the space required to store backups. Open Time Machine preferences to select a larger backup disk or make the backup smaller by excluding files."

Checking the drive via finder says that I still have north of 400GB available. Does anyone know what's happening here?

Thanks