Locating Time Machine disk image and understanding its capacity on MacBook Air

how to locate disk image used for Time Machine backups?


I have a MacBook Air that has a 251 Gb internal drive

One of the Time Machine destinations appears to be a Disk Image.


I am confused about the location of the disk image.


The disk image says that the capacity is 16 TB. Perhaps that is the theoretical maximum capacity of that kind of disk image, so that in itself might not be relevant.


The disk image says that it has 332 GB free. However, 332 GB is larger than the entire disk drive.


The 332 GB cannot be a theoretical capacity remaining, as the theoretical capacity is 16 TB and the used capacity is supposedly 107 GB, leaving about 15.9 TB theoretically remaining capacity.


If the remaining capacity for the Disk Image was no more than the remaining capacity of disk1 (about 137 GB) then it would be clear that the Disk Image was sharing space with disk1 -- but with the remaining capacity being larger than the hard drive size, I am left confused about where the capacity is being measured from.



Interestingly, the Disk Image disappears from Disk Utility when Time Machine has not been recently running, and

I cannot Go To Folder when it does not show up in Disk Utility. Also, I cannot see the folder anywhere in Finder (short of Go To Folder), even though I configured Finder to show everything in the sidebar.

MacBook Air (2018 – 2020)

Posted on Aug 22, 2026 6:38 PM

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6 replies

Aug 23, 2026 8:36 AM in response to sandra-leigh

sandra-leigh wrote:
I am confused about the location of the disk image.

It's on the server that is hosting your remote backup.


The disk image says that the capacity is 16 TB. Perhaps that is the theoretical maximum capacity of that kind of disk image, so that in itself might not be relevant.

It's the size of your server.


The 332 GB cannot be a theoretical capacity remaining, as the theoretical capacity is 16 TB and the used capacity is supposedly 107 GB, leaving about 15.9 TB theoretically remaining capacity.

Could be a defined limit on the Time Machine allocation on the server. Or it could be that the disk image gets reallocated periodically to accommodate future backups. Either way, it's no big deal.


Aug 23, 2026 7:13 AM in response to sandra-leigh

As is said, a picture is worth 1000 words.

To help us help you, would you please launch Disk Utility, click View > Show All Devices and then provide a snapshot of what the app displays in its sidebar?


Then also, please launch the Terminal app and type and execute this command:

diskutil list


You will be presented a list of the drives and volumes that your Mac can see. Please provide a screenshot of that, too. It will look something like this:




Aug 22, 2026 9:09 PM in response to sandra-leigh

If you are backing up to a directly connected external drive, which appears you are, there isn’t an image at all. There will be a date/time-stamped folder for each backup

Network backups will have a Sparse Bundle disk image.


You have about 100GB of data to back up and 110GB used on the backup drive. I don’t know why it is not reporting the correct amount of free space. It has nothing to do with a hidden disk image. There isn’t one.

Locating Time Machine disk image and understanding its capacity on MacBook Air

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