Finder "copy" - automatically verifies?

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Level 1

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Finder "copy" - automatically verifies?

I'm copying a lot of files from one external drive to another, and it made me wonder how good Finder is at verifying that everything is copied correctly...

Does anyone know if the Finder "copy" command uses any type of checksum verification to ensure that the a file was properly copied?

If I use Finder's "copy" to move over a bunch of large folders, and the copy job completes without any error messages or anything like that, can I be confident that everything properly was copied? Or do I have to do something else to verify this? (And if so, all suggestions are welcomed.

Thanks

Mac mini, OS X Mavericks (10.9)

Posted on Dec 10, 2013 1:26 PM

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Answer 1

Stridr8808 Author

Level 1

5 points

Dec 10, 2013 6:36 PM in response to Stridr8808

Wanted to get this back on the page so someone who knows the answer will see it...

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Answer 2

Linc Davis

Level 10

209,547 points

Dec 10, 2013 7:27 PM in response to Stridr8808

The Finder is not open-source software. No one outside Apple knows the answer to your question. All modern storage devices perform error correction at the hardware level.

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Answer 3

Stridr8808 Author

Level 1

5 points

Dec 11, 2013 9:34 AM in response to Linc Davis

So would it be a good idea to run third-party verification software? Or is that not necessary?

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Answer 4

Linc Davis

Level 10

209,547 points

Dec 11, 2013 9:40 AM in response to Stridr8808

Unless you're getting error messages that indicate a disk failure, the chance that file will be randomly corrupted is very small. However, if you can't tolerate that small risk, then you should use third-party software that does verified writes. I don't have a specific recommendation.

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Answer 5

Jul 26, 2015 12:36 PM in response to Stridr8808

I'd also like an easy and cheap GUI that could handle both copy and verify at once.

Is there any?

arRsync seems to be abandoned 9 years ago, just like some other rsync GUIs I googled...

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Answer 6

Jul 26, 2015 4:55 PM in response to Toke Lahti

...Grsync is 3 years ols and ditched 2 years ago...

CCC is mighty and dandy and I've used their free version a lot, so I guess I own them a little, but it's 40 bucks!

At the age of one-dollar-app-store there should be something between zero and $40...

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