Mac OS X 10.8.2 Shows wrong available disk space

I've experienced this problem a few times. For me, it's always been because of local Time Machine snapshots. Try toggling Time Machine off and then back on. This fixed the issue for me – it seems to clear out the local snapshots (Disk Utility counts local snapshots, whereas Finder doesn't).

You could also try forcing a manual Time Machine update (e.g., click "Back Up Now"), although I haven't tried that.

As for the Finder automatically deleting these local snapshots when disk space gets low… it won't if you're trying to copy a large file (it fails the pre-flight check). That behavior should be reevaluated by Apple engineers.

The reason why I simply had to resolve these numbers was because I use an app "Quick Disk". What is primarily does is it allows me to quickly eject which ever disks I choose, and also presents very neatly the remaining amount of space in each disk in a very neat looking UI.

Unfortunately, this app seems to pull its data from the same place that showed the incorrectly 'smaller' space. So when in fact I had 78 gb free on my hard disk, it showed only 30. I cant stand seeing that, so I had to find a fix.

Besides, I dont think switching time machine off then on again compromises the backups too much - although I am no expert here so pardon me if I'm wrong.

Edit: I am aware that even though the "smaller" space isnt indicative of how much space there really was, it kinda defeats the whole purpose of me buying this app if it doesnt show me exactly what I want to know.

I just updated to 10.10.3, and updated XCode on my MacBook Pro (15-inch, Early 2011)

The finder status bar showed 703TB; about this Mac shows the "real" 500 GB hard drive size, but the "703TB backups fill the display bar.

I toggled Time Machine, and the finder windows now show 240GB free...

The app store shows the iTunes 12.1.2 update and the OS X Updates, but not the XCode update.... weird.

Rebuild the Spotlight index by following these instructions:

Spotlight: How to re-index folders or volumes

Hi shamalk!

Did you already solve it? If not, did you alredy tried to verify or repair your drive using Disk Utility?

I also own a mid 2012 Macbook Air, and although my "About this Mac" disk info seems consistent, it differs from Finder info, but this is because Finder ignores Backups (wich is ok).

I didn't see this the first time around, but note that this is 100% normal. Disk Utility and the storage display both include Time Machine's local snapshots in the used space. The Finder does not, because those snapshots will be automatically deleted if free space gets too low, so they are considered to be equivalent to free space. For more information on this, see:

What are Local Snapshots?

The Storage Display

Also, note that I'm not sure why an update would fix the "problem," as it should still be behaving the same way.

Ahh, yes, if it's adding up to more than the possible space on your hard drive, something is wrong. If an update fixed it, I wouldn't worry about it. For others, if it persists, it may mean that there's a problem with the drive.

I agree. Anyone experiencing a discrepancy between the free space shown when you Get Info on the Macintosh HD, and looking into About This Mac > More Info > Storage, toggling the Time Machine switch off then on again fixes everything.

I experienced this issue about a couple of months ago, and again today. Both times this fixed it and now I have the correct amount of space shown in all places.

I agree. Anyone experiencing a discrepancy between the free space shown when you Get Info on the Macintosh HD, and looking into About This Mac > More Info > Storage, toggling the Time Machine switch off then on again fixes everything.

That's because that deletes your local snapshots. So, really, you're compromising your backup system in order to make two numbers that really don't matter that much agree with each other. That doesn't make much sense.

Besides, I dont think switching time machine off then on again compromises the backups too much - although I am no expert here so pardon me if I'm wrong.

See the link about local snapshots that I posted. If those backups are something you can live without, toggling Time Machine may not be harmful.

Of course, getting too concerned with your free space in the first place isn't very productive. If disk space is getting tight enough that you have to keep looking at it, you need a bigger disk (or need to delete some files), since a nearly-full hard drive kills performance.

Nosferius wrote:

I've also confirmed this trick works for OS 10.9 Mavericks

Please note what I said about this "trick" back in February:

That's because that deletes your local snapshots. So, really, you're compromising your backup system in order to make two numbers that really don't matter that much agree with each other. That doesn't make much sense.

Hi Thomas,

In my case it concerned a mac that was imaged using a default image we have here and was for some reason giving the issue as shown in the original post. The mac was not back-upped yet nor did it need one so I could do this without thinking 🙂 but of course I would think twice when I'd have this issue on a mac with a lot of user data on it 🙂

Of course if someone has a resolution for this problem that uses a different method I'd love to hear it.

Nosferius wrote:

Of course if someone has a resolution for this problem that uses a different method I'd love to hear it.

You're still thinking about it wrong. As has already been said, this is not a "problem," it's simply a difference in how different programs report free disk space. There is no "solution," per se, except to be aware of the difference and why it exists.

If you are ever in a situation where you need to keep track of every megabyte of disk space, you probably need a larger disk. We are long past the days when you could reliably expect to know exactly how much free space there is.

Thomas_r,

I understand what you are saying, and I read the link to describe local snapshots.

I have same problem with Disk Utility and finder not matching up, but they don't mach up by more than 250 GB. What prompted this was tech tool gave me a warning for less than 10% disk space, but I have close to 30% actually available... I went to Disk utility to see what was up and it failed verification, so I ran repair from a recovery startup.... it failed. I switched off the time machine, and back on, restarted into recovery and repaired, success.

So the question is, based on your warning, why wouldn't I want to delete the local snapshots if they are causing a problem, especially when I have proper backups on two time capsules?