rsync seems to overwhelm a failing hard disk

[Kevin Korb]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

The best tool for getting data off of a failing hard drive is
ddrescue: http://www.gnu.org/software/ddrescue/ddrescue.html

Make sure you run it with the log file option.  You can run it
multiple times possibly with power cycles in between and it will
attempt to get the parts it couldn't get before.  You can also tell it
to go backwards so maybe it can get a bunch of blocks before it hits
the bad part again.

If you already have an rsync backup of the disk (you really should)
then making a new backup with --link-dest or similar before resorting
to the ddrescue can be a good idea.  That way maybe there will be no
changes that actually need to be backed up that are actually bad
sectors (lucky!).  Otherwise you will get as many changed files as you
can without touching your pre-disk problem backup which has data that
may be old but is at least valid.

On 11/25/13 16:41, Chris Dennis wrote:
> Hello rsync people
> 
> Today I was recovering data from a beginning-to-fail external USB
> hard disk.
> 
> I started with my usual 'rsync -av --ignore-errors <source>
> <dest>', and that was fine until it got to the first I/O errors.
> It paused but continued after the first couple of errors, but then
> the disk started buzzing and rsync gave error messages for every
> file (I'm afraid I didn't note the exact text of the messages).
> After that, every run of rsync (trying to --exclude the faulty
> files and folders) started the disk buzzing again, and rsync
> couldn't copy anything.
> 
> The curious thing was that after replugging the disk, I was able
> to manually drag-and-drop a lot more files from the disk via the
> Debian desktop.  Trying rsync again quickly caused the buzzing
> problem again.
> 
> In other words, a simple file copy was able to read the disk when
> rsync gave errors.  Is that to be expected?  Is there a way to make
> rsync more gentle on a fragile disk?
> 
> cheers
> 
> Chris

- -- 
~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~
	Kevin Korb			Phone:    (407) 252-6853
	Systems Administrator		Internet:
	FutureQuest, Inc.		Kevin at FutureQuest.net  (work)
	Orlando, Florida		kmk at sanitarium.net (personal)
	Web page:			http://www.sanitarium.net/
	PGP public key available on web site.
~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~'`^`'~*-,._.,-*~
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.22 (GNU/Linux)
Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/

iEYEARECAAYFAlKTxxkACgkQVKC1jlbQAQc++QCdGyIADBJHNbHol8phskz/7imJ
so0Ani9NGYuuckVJQMoCxZI+MMaO7K15
=9yD1
-----END PGP SIGNATURE-----