I'm in the process of decrypting an external drive. The drive is connected to a USB 2 Port on my Early 2011 MacBook Pro (2 Ghz Intel Core I7 running High Sierra). The drive is 8T and it has 3T used. Encrypting the drive took three days but much data has been added since. Checking the progress of the decrypting shows that it's only decrypting 2% per day and at this rate it will take an additional 38 days to complete (the drive nor the computer never sleep). My question is, can I safely stop the de-encryption on this old mac and finish the task on a faster brand new iMac (3 GHz 6-Core Intel Core i5 running Catalina) without loosing all of my data?
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Decrypting external drive, is it safe to switch computers part way through?
- Thread starter John Sterlin
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I could be entirely off base but I believe the process would just start over but run at least somewhat faster on a newer machine given newer processors have hardware decoding.
That’s my “I’m an IT guy but I can’t speak *specifically* to your question” understanding.
That’s my “I’m an IT guy but I can’t speak *specifically* to your question” understanding.
Thanks for your input, there is just so little out there on the topic of decrypting. I would just try it but the data is important so I can't afford to risk it. Probably the last time I encrypt a drive unless this process becomes smoother.
This is why I NEVER "encrypt" drives (with one small exception, a backup drive I keep in my car, but it has only about 20gb of data).
Suggestion:
Don't try to UN-encrypt the drive.
Instead, get ANOTHER drive large enough to hold the contents of the encrypted drive.
Then... use either CarbonCopyCloner or SuperDuper (both are FREE to download and use for 30 days) to create a clone of the source drive onto an UNencrypted backup.
The process should go MUCH MUCH more quickly.
When done, you should have all the data in an exact copy of the source drive, except there will be NO encryption.
Then... just erase the encrypted drive using disk utility, but DO NOT encrypt it when doing so.
Suggestion:
Don't try to UN-encrypt the drive.
Instead, get ANOTHER drive large enough to hold the contents of the encrypted drive.
Then... use either CarbonCopyCloner or SuperDuper (both are FREE to download and use for 30 days) to create a clone of the source drive onto an UNencrypted backup.
The process should go MUCH MUCH more quickly.
When done, you should have all the data in an exact copy of the source drive, except there will be NO encryption.
Then... just erase the encrypted drive using disk utility, but DO NOT encrypt it when doing so.
Wish I would have done this before I started... now that I'm days into it it's impossible to stop and I'm afraid a copy of a partially encrypted drive will be a mess.
The silly thing is, I didn't "need" to. I got a new iMac and I got it in my head that "hey, I should decrypt this drive on my old Mac so I could move it to my new Mac" about 10 minutes into decrypting I realized that that was pretty dumb. Too late, apparently you can't stop once it starts that and now I'm 33% into it at 2% per day. I want this drive on my new mac but I'm mortified to move it until it's done. The external and old mac have been running non-stop and both are very warm.
I wouldn't. I was encrypting a drive, which somehow got corrupted during the encryption process. It was unmounted during the process a few times; I had forgotten about the encryption totally. The drive looked fine, but disk first aid gave some sort of odd encryption-related error and the files were all bad.
Luckily I had a backup.
Luckily I had a backup.