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Re: [Pan-users] Error Correction
From: |
Douglas Bollinger |
Subject: |
Re: [Pan-users] Error Correction |
Date: |
Wed, 18 Jun 2003 10:03:08 -0400 |
On Wed, 18 Jun 2003 13:50:58 +0100
address@hidden wrote:
> Yesterday I was kinda "flipping through" freshmeat and found the
> following site:
>
> http://freshmeat.net/projects/parchive/
>
> Description is as follows:
>
> Parchive is a tool to apply the data-recovery capability concepts of
> RAID-like systems to the posting and recovery of multi-part archives on
> Usenet.
>
> Just wondering, does PAN have any built-in error-correction code, for
> those "just-in-case" cases?
Hmmm, I'm not sure what you mean.
In certain binary groups that specialize in _really_ big files, like 700
meg AVI files, the posters usually use rar file compression, which breaks
the file into many chunks (with a little compression) and make a few parity
files as well. The parity files are "magic" files than can reconstruct any
of the missing rar file chunks at a one to one ratio (one parity file per
missing rar chunk). This way if a file is dropped along the way, which
happens frequently, you can use a parity file to replace the dropped file
without bugging the poster for a fill all the time. I don't think you have
to use par with rar, but this is the way it is usually done.
I'm not sure what this has to do with Pan. Right now, you d/l the file
chunks with Pan and run rar/par by hand which is fine by me. With the size
of these files, I don't think this process would automate very well.
--
You can't hurt me!! I have an ASSUMABLE MORTGAGE!!