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visits member for 3 years, 5 months
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Dec
11
comment What is the UUID format used by LVM?
That is true indeed, also blkid. Is there a logical relationship between the "internal" UUID and the actual one shown.
Dec
11
asked What is the UUID format used by LVM?
Nov
20
comment How can `dd` be used to right-shift data blocks?
I agree that this is a potential issue but I haven't looked at the edge cases, since I was able to use it to do what I needed. There are ddrescue options to limit its attempts to recover bad data but I haven't looked into using them.
Nov
20
accepted How can `dd` be used to right-shift data blocks?
Nov
20
comment How can `dd` be used to right-shift data blocks?
I accepted this because it answers the original question by demonstrating how dd could be used. I think, however, that the real solution is not to use dd but instead opt for something that is designed to run backwards like ddrescue. I've described a way to do that in an answer.
Nov
20
revised How can `dd` be used to right-shift data blocks?
added a summary relating to the original question.
Nov
20
comment How can `dd` be used to right-shift data blocks?
re the block size, I had tried larger blocks (I should have written that in the question). I found that it didn't become more reliable even a 64K sector buffer. The reliable solution is to run backwards, something that dd doesn't do.
Nov
17
revised How can `dd` be used to right-shift data blocks?
update
Nov
14
answered How can `dd` be used to right-shift data blocks?
Nov
14
comment How can `dd` be used to right-shift data blocks?
Re the filesystem, are you referring to the filesystem containing my test file? That's ext4 but for the block device copy, any filesystem should be irrelevant.
Nov
14
comment How can `dd` be used to right-shift data blocks?
That makes sense when reading it and I'm going to take another look based upon that. But it doesn't explain why it worked on the test file.
Nov
14
comment How can `dd` be used to right-shift data blocks?
@psusi, the second md5 is output by mbuffer (its -H argument enables this feature).
Nov
13
comment How can `dd` be used to right-shift data blocks?
@Celada - the 100MB example was just an example. Reading 1TB, for example, in one go wouldn't be such a good idea.
Nov
13
accepted Is there a special variable containing a case statement match
Nov
13
comment Is there a special variable containing a case statement match
Yes, I've used this technique before but it is a little brittle. I think as a solution for bash this is probably as good as it gets!
Nov
13
asked How can `dd` be used to right-shift data blocks?
Nov
11
revised Is there a special variable containing a case statement match
added more detail in response to a comment.
Nov
11
comment Is there a special variable containing a case statement match
@Hauke Laging - yes you can. I'll add a contrived example to the question to illustrate it.
Nov
11
asked Is there a special variable containing a case statement match
Nov
5
accepted with sed, how can I replace word within a matching line?