Re: Results of CheckDS.py

On Mar 5, 2007, at 3:45 AM, Toby Dickenson wrote:

> (can we keep replies on list please)

	Sorry, this happens whenever I run into a list that doesn't default  
to replying to the list.

>> 	I still have some bad MD5 checksum files that were created after my
>> last good backup. IOW, there are no backups of these that differ from
>> the current bad file. I tried deleting them, but now if I try to
>> pack, I get an error about the file is missing. If I restore it from
>> the backup and try to pack, I get an error about a bad checksum.
>> Catch-22!
>
> Yes, packing will only delete things after proving that it has a  
> full correct
> copy of everything it needs. If anything is missing or wrong, then  
> it can not
> draw any conclusions about what data is unneeded and can therefore be
> deleted.

	OK, that makes sense.

>> 	Can I replace the file with either an empty file, or a copy of
>> another uncorrupted file to get around this problem? How can I ever
>> pack this bloated system?
>
> If you want to suppress the checksum checks then you have two  
> options. The
> easy (but crude) approach is to turn off the checks using the  
> config/settings
> file. A better solution is to selectively suppress the checksum for  
> each file
> that you know to be affected. The 16 bytes starting at address 40  
> are the md5
> checksum for the remainder of the file. Setting this to all-zeros  
> indicates
> that the md5 has not been calculated, and will not be checked.

	That worked! I wrote a short Python script to replace those bites  
with chr(0), and I was able to pack once again. To give you an idea  
as to what a difference this made, my last full backup created a 13GB  
file. I just ran a full backup, and the file size was 2.7GB!!

	Thanks again for your help.

-- Ed Leafe
-- http://leafe.com
-- http://dabodev.com



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