On 2016-12-07 13:26, Anton Aylward wrote:

On 12/06/2016 11:34 PM, John Andersen wrote:

...

...

Greg Freemyer

Doesn't rsync hash files on both ends to find which files need to be synced?

If so, wouldn't another rsync run find any differences?

Why would you need another tool?

Indeed. From the man page:

-c, --checksum ... Note that rsync always verifies that each transferred file was correctly reconstructed on the receiving side by checking a whole-file checksum that is generated as the file is transferred, but that automatic after-the-transfer verification has nothing to do with this option’s before-the-transfer "Does this file need to be updated?" check.

Note from that: rsync *always* verifies ... after the transfer.

Yes. You can do a second run with checksum enabled, and it will compare the checksums at both sides, again. I do this for archival media. -- Cheers / Saludos, Carlos E. R. (from 13.1 x86_64 "Bottle" at Telcontar)

On Tue, Dec 6, 2016 at 11:49 PM, Philip Amadeo Saeli wrote:

* Greg Freemyer [2016-12-06 22:13]:

...

I should know this, but ..

I'm moving hundreds of thousands of files from USB drives to a new destination drive.

I've used rsync to make a copy of the files which is great.

But I need to ensure all the files are exact copies. I don't think rsync has a "hash destination and report disagreements with source" feature.

Is there a tool for doing that?

fyi: I have a windows cmd line tool for doing this, but I'd rather work in linux.

I've used something like the following:

$ rsync -n -cv [other rsync args...]

do to the comparison. The "-c" flag directs rsync to use a 128-bit checksum to compare the files. Of course, "-n" inhibits any actual copying. I also generally use the "--log-file=<log-file>" arg to direct the output in to a file instead of the terminal.

Using the "-c" arg can be rather slow, but more certain than relying on file size and mtime only.

Hope this helps!

-- Philip Amadeo Saeli psaeli@zorodyne.com

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Thanks very much. That seems to be exactly what I was looking for. I'm not sure how I didn't know about that already. Greg -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org