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Recovering Deleted Files on ReiserFS3?
DarkSarin asks: "I have a rather serious problem: I managed to accidentally delete some files (rather important ones at that!) while trying to back them up to cd (I was using a GUI burning software that will remain nameless for now). How do you recover accidentally deleted files in Reiserfs? This thread (started by me) indicates that you can't recover them. Note that I had found a way to rebuild the tree, but that didn't work. It seems odd to me that you wouldn't be able to recover accidental deletions, but that really does seem to be the case. Help? Please?"
First off, I have several questions. Do you have an original copy of the partition before you started running recovery tools (after you deleted the file, but before you created new ones)? If not, make an image immediately. You want the most original image you can find. Now, the second question, is how much data am I a looking for, and how large is the partition? (How large is the needle, and how large is the haystack?). What type of data am I looking for? Is it a word document? A text file? A gif? A jpg? Some html? A PDF? The smaller the file, the more likely that if it got overwritten, it all got overwritten. However, the more likely you are to recover all of it. If it was a very large file, it's possible that you can recover pieces and parts, but not all of it. Now, it's my understanding that you can recover anything written to a harddrive, even if you have overwritten it several times. However, it's very, very expensive to do so. So now the question is how much money is it worth to you? The guys as ReiserFS probably have the best shot at helping you. They probably don't want to however. The more you know about the order of the files in the directory, the more you know about how the files were constructed, and the order files got put on disk the better. They you can make better educated guesses about the sequence in which the pages got allocated to know where to go look for the file. Do you have anything on the drive you are worried about posting? Can you post an image of the drive? I'm not an expert in this area, but I've seen people recover mail spools at an ISP using dd. People leave ISP's over losing all their mail, so they worked really hard at it (however, that was an ext2 filesystem). Kirby
If you had this problem then I or anyone will have this problem too, so please let us know what program you are talking about. Was a user error? Was it a bug? Is the bug being worked on?
Useless sig.
...every Windows user looks at that Recycle Bin shortcut on their desktop and smiles.
(No, that's not really a troll. Human error happens.)
A lot of higher end storage appliances and some filesystems support file versioning. Even NTFS has streams which cna be used to version a given file.
/var /tmp /usr
/home.
As to files being created and destroyed frequently, this is why we partition into at least:
/
swap
obviously var and tmp would not be a place to version files.
you could consider the use of versioning in a place like
The problems with this are in efficiency. Leaving the files in place would create fragmentation problems. Moving them to another part of the disk would result in a lot of unnecessary disk activity.
Periodic backups are a much better answer.
Schemes like this would also require the fs to delete old files when the space is needed, but this is what is done now. The data is still there until the space is used by something else (and even after that for all of you super security freaks). Given, the choice of what to delete could be made in a manner to use the least recently deleted space first, but this would again cause efficiency problems.
But it can be helpful in the future to dedicate, say 10% of your drive to an LVM snapshot space....
:)
I haven't done this yet (I'm lucky! I have a real tape drive to backup my stuff.....) but I plan to make my system take a snapshot every hour and every day (total of two) so that at most I lose an hour's worth of work.
Also, I've always wondered if it was possible to make an operating system that would take as long to destroy something as it did to create it. For example, your term paper took ten days to write, so the rm termpaper.tex command would take ten days to run
Fellowship 9/11
How do you recover accidentally deleted files in Reiserfs?
It's really easy. You just restore from backup.
Perhaps also you don't understand that I /like/ holding shift. Delete is a powerful word, you must use it with care.
-- 'The' Lord and Master Bitman On High, Master Of All