Suddenly 20GB extra free disk space in Finder

[brilliantthings]

Turned on my MacBook Air (2010, 4gb, 256gb) today and I suddenly have 71GB free space according to Finder. I had 53GB yesterday.

The strange thing is that Disk Utility still identifies 53GB of free space today.

Disk Utility is happy with the disk. Had to repair some disk permissions, but this didnt change the free space in Finder.

Why are Finder and Disk Utility disagreeing and what can I do about it?!

 

[DesertEagle]

Have you emptied the Trash?

 

[brilliantthings]

Have you emptied the Trash?

Ya.

 

[Weaselboy]

Why are Finder and Disk Utility disagreeing and what can I do about it?!

Are you using Time Machine? If so, local backups can cause this and it is normal. The Finder space available does not account for space used by local backups.

 

[brilliantthings]

Are you using Time Machine? If so, local backups can cause this and it is normal. The Finder space available does not account for space used by local backups.

Spot on. I've been out of town and away from my Time Machine Backup drive for 10 days. But explain this:

I have 71GB free space according to Finder and 53GB according to Disk Utility.

About This Mac Storage section says 18GB is being used for Local Backups. So that makes sense.

But before I left home I had 53GB free space on Finder. Shouldnt I have less space according to Finder now that I'm away from my Time Machine Disk and the computer has made 18gb of local backups?

 

[Weaselboy]

Spot on. I've been out of town and away from my Time Machine Backup drive for 10 days. But explain this:

I have 71GB free space according to Finder and 53GB according to Disk Utility.

About This Mac Storage section says 18GB is being used for Local Backups. So that makes sense.

But before I left home I had 53GB free space on Finder. Shouldnt I have less space according to Finder now that I'm away from my Time Machine Disk and the computer has made 18gb of local backups?

Finder ignores the local backups when calculating free space, so it should not matter either way. What you can do it turn Time Machine off then back on and that will zero the local backups. They will begin to accumulate again, bit it gets it back to zero for now.

 

[brilliantthings]

Good stuff. Thanks.

 

[brilliantthings]

Just realised that Finder had probably been miscalculating my free space for a while and had been including the Time Machine backups in its used disk space calculation. That's why I had only 53gb free space for the last month or so. I'd been wondering why I had so little space. Not sure what fixed it. Time Machine must have recalibrated once I moved away from its disks. Great news.