Gentoo Archives: gentoo-user

From: Adam Carter <adamcarter3@×××××.com>
To: "gentoo-user@l.g.o" <gentoo-user@l.g.o>
Subject: Re: [gentoo-user] The sudden disappearance of ....WHAT??? (I/O error on a SD flash card?!)
Date: Sun, 26 Mar 2017 09:10:47
Message-Id: CAC=wYCEGa+RJrT+CDsfUponH50C+75KzvbkBLNC-Vmbnb2i8qw@mail.gmail.com
In Reply to: Re: [gentoo-user] The sudden disappearance of ....WHAT??? (I/O error on a SD flash card?!) by Bill Kenworthy
1 > Currently I am ddresucueing the flashcard to the harddisc.
2 >>> Next I will try to mount the sdcard.
3 >>>
4 >>>
5 I hope you meant to say "mount the sdcard image". Once ddrescue has done
6 its best, you wont try to use the sdcard again.
7
8 Also, you probably want to copy the image first, because when you try to
9 fix it you will perform writes, and you dont want to lock yourself out of
10 other recovery options by making potentially damaging writes.
11
12
13 > What reliable sdcard-reader can one recommend ?
14 >>>
15 >>
16 I'm not sure what you mean here given that you're making an image with
17 ddrescue.
18
19 Is the assumption correct, that -- if ddrescue could read each
20 >> partitions of the sdcard without stuttering, retries and errors --
21 >>
22 > the sdcard itsself is ok and "only" the logical structure
23 >> (fs, superblock etc) got damaged?
24 >> Or do I overlook something?
25 >>
26 >
27 If ddrescue can read it cleanly with no retries (in which case it will
28 offer no benefit over dd) then yes, I agree. However, given the cost of a
29 card and the cost of your time and the risk to your data, I wouldnt be
30 using it.
31
32
33 > I dont know of a cdparanoia type recovery utility for sdcards but I
34 > suspect sdcard design means that approach wont work.
35 >
36
37 I would just use photorec against a copy of the image. I have done this in
38 the past and recovered many files from a ddrescued image of a failing USB
39 drive, however, all the filenames were lost.

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