Mac OS - best method for cloning a disk

I’m going to make a backup of a 15tb Pegasus to another drive (Mac OS). What is the best/preferred way to copy all over, with verification, no pw prompts in the middle of it, no sys files missed, etc.? Thanks in advance.
I used Carbon Clone or something a while back and I think it worked well. But curious about other ways.

Yeah I am a fan of CarbonCopy. We have been using GoodSync quite a bit also.

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I don’t understand exactly how these copying programs since I’ve never had cause to, but it seems to me that a good old fashion rsync could do everything you’re asking. Maybe thats too facile a solution though?

rsync is the thing I forgot about. I can’t remember the commands though.

The basic command is more or less

rsync -aP [file path to drive you want to copy] [file path to drive you want to write to]

so in a hypothetical drive to drive transfer on a Mac the command might be something like this

rsync -aP /Volumes/Macintosh\ HD/ /Volumes/newDrive/

The -a flag stands for archive which is a combination of all the most important flags. It will make sure that all of the files are copied exactly the same as they are on the original disk. The -P flag stands for progress which will make the command verbose in the terminal and show you how many files total are being transferred, how fast, and how many are already transferred.

If you want to check through all of the options available you can just type rsync --help in a terminal and it will display everything you can do. It can be intimidating to look through all the different flags, but you really just need the above command to do basic transfers. Its a non-destructive process so there isn’t much risk of something going wrong. Worst case you copy the wrong files to the wrong location. My suggestion would be to start small with just one file or folder. Confirm that the transfer worked using Finder and that the command is properly configured, and then go for the whole thing.

Its nice because rsync is relatively intelligent so if your transfer is interrupted you can just run the same command again and rsync will go through all the files, figure out whats already been transferred and then resume with the untransferred files. Also less risk of some program not being willing to let go of a drive, and requiring force ejection or some other crap that happens with Macs and harddrives.

Happy to help troubleshoot if you want to go down the rsync path.


Awesome. Thanks a bunch, Ryland.

I believe carbon copy cloner is just a nice interface to rsync.

Ive been using it for years and very happy with it. Well worth the money

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