verifying contents of hard drives

[Sossity]

I found an older external hard drive A, of which I think but am not positive that I copied all of its contents onto a newer external hard drive B.

I would now like to wipe clean drive A to sell on eBay, but I want to be sure I have all of the content from it copied onto drive B before permanently wiping drive A clean for selling.

Is there a way I can do this on the whole, without tediously going through every file and folders on both drives to check by hand using finder.

Maybe an app or something?

 

[satcomer]

I found an older external hard drive A, of which I think but am not positive that I copied all of its contents onto a newer external hard drive B.

I would now like to wipe clean drive A to sell on eBay, but I want to be sure I have all of the content from it copied onto drive B before permanently wiping drive A clean for selling.

Is there a way I can do this on the whole, without tediously going through every file and folders on both drives to check by hand using finder.

Maybe an app or something?

Just Boot into Disk Utility to wipe the drive!

 

[Weaselboy]

Maybe an app or something?

Use the app Carbon Copy Cloner to run a copy (clone) from A to B. It will go through and look for items on A that are not on B and move them over. If you want to be extra sure, there is a verify option that takes a little longer to run that compares each file after the copy to make sure an exact copy got moved over without errors.

The app is $50, but they have a 30 days trial if you just want to use it for this and ditch it.

http://bombich.com/download

 

[Zazoh]

As you can see, there are many ways to skin a cat ...
I'd sync using rsync from the terminal, comes with mac. If you use the archive flag, only different files will be copied.
http://www.haykranen.nl/2008/05/05/rsync/

 

[Fishrrman]

Recommend what Weaselboy posted above.
Use CCC to clone A to B.

CCC is FREE to download, and it's FREE to use (fully functional) for the first 30 days.

Once the clone is done, you can re-initialize A.