"Isn't enough free space" error copying from external drive

Dec 15, 2014
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I'm trying to copy a 150 GB file back onto my computer from an external drive. I have 375 GB of space on my computer, but it keeps saying there isn't enough free space and I can't get the file back on my computer. I've emptied the trash, restarted the computer, and searched around on the internet and can't find a solution.

Any help would be great!


Sep 17, 2014
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It would be good if you can tell us 1) what exact OS version you are using, and 2) what Mac model you are using. That would be useful.

In any event, Disk Utility can be used to Erase Free Space, but you need an "external" way of doing that. There are a couple of ways of doing that, and one of them depends on the OS you have. Here are the choices:

1. If you have a SuperDuper! or Carbon Copy Cloner backup (on an external device), you can boot your machine from that backup, and run Disk Utility from there.

2. If you have OS 10.7 (Lion) or later on your machine, you can "get" to the Recovery HD partition by holding down the Command and R keys when you start up your machine. (If you can do that, be patient, as it doe stake some time). Once you do that, a menu will be presented, and one of them is Disk Utility. Select that one.

3. If you Mac has DVD drive, and you have the OS DVD, you could boot your machine from that, and then run Disk Utility from the DVD.

If erasing the free space does not help, then you will need to make a bootable backup, boot the machine from that bootable backup, run Disk Utility from there to Erase your internal drive, partition it if necessary (that depends on your needs), and do a restore from that external backup to your internal drive. The best software to use for the backup is the "free" version of SuperDuper!. You can get it from here:


I use SuperDuper!, and I can tell you that its' backup/restore work flawlessly, and are a life saver!

By the way, it would be good to get in the habit of making backups. Assuming your OS is recent enough, you can use Time Machine for that, but it is difficult, at best (not even sure if it's possible) to boot from a Time Machine backup and do a restore. I already mentioned above the two best products for having a bootable backup from which you can restore from.
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