Corrupt Archives

[gworley]

I have run across some corrupt archives. And have had problems extracting the contents using Servant Salamander.

Servant Salamander will only extract the "good" files and will not partially extract the "bad" files. The CRC is wrong on these files, however, when I go use the undelete function of SS, I find the file there and copy it else where... 95 percent of the the time this file is 100 percent there even though the CRC is wrong. It would be nice if I was asked if I want to save the partially recovered file -- i.e. "Only 98% percent of the file was able to be extracted would you like to save the extracted file?" This would save some steps to recover the partially recovered file in the archives.

Current output is says something about wrong password? These archives are not passworded. A CRC error doesn't mean that the archive has a bad password as you cannot extract any of the file with a bad password. In fact if the password isn't supplied correct on a passworded archive you get the wrong password message in SS.

To me this is a bug. You should have the option of extracting the corrupted file from the archive for partial to full recovery.

Thank you,

George Worley

[Jan Rysavy]

George, do you mean corrupted ZIP archives?

You are right that Salamander could be stronger in archives recovering. Also we can go ahead with Undelete plugin and support corrupted partition recovery.

Now you can use specialized tools for these tasks (examples only):
WinZip, WinRAR, 7-Zip for archive recovery.
R-Studio for partition recovery.

From our point of view this is a feature request.

[gworley]

Thank you for your reply....

Yes I mean .ZIP files and .RAR files as opposed to partitions.

WinZIP gives little options for recovery of corrupted .ZIP files. Their website in fact guides you to InfoZip's command line based utility for recovery. InfoZip doesn't deleted the files when invalid CRC is encountered.

WinRAR has utilities built-in for recovery but I have yet get it to recover any files -- I just tested one and it gave me a file called Rebuilt-Test.RAR and when I went to extract sample.avi got the same error is before. They include UNRAR.EXE which is a command line utility which will with options let you save files with invalid CRC's.

For partition recovery I use Restorer Pro 2000.

I wasn't sure where to put this because of the "Password" listed in the message that popped up when in fact it cannot be a password issue. Also, to me when you are extracting files from .zip or .rar, the expect result wasn't achieved... this is also a fault with WinZIP and WinRAR... the expect result for me is the extracted file to be there no matter if there is a CRC error --- to me you report the error but don't delete the file.... the new feature would be to ask if you want to delete the file -- the file is already on you hard drive. This is a the expected results in the command line utilities and to me should be the expected results in the GUI utilities that do the same thing.

Thank you,

George Worley

[Jan Patera]

he expect result for me is the extracted file to be there no matter if there is a CRC error. This is a the expected results in the command line utilities and to me should be the expected results in the GUI utilities that do the same thing.

This may be the expected result for power users (like command-line utilities are), but definitely a very dangerous result for BFU or nearly-BFU which (like or not) defnitely prevail. Having the damaged file left on HDD is a good idea, but definitely deleting corrupted files must be the default behavior.