Hmm - how about linking bzip2 to zip/compress
whatever you call you get bzip2 ??
On 16 Nov 2000, John Goerzen wrote:
> Hi,
>
> I'd like to use bzip2 with amanda for two reasons:
>
> 1. It compresses a lot better than gzip
>
> 2. More importantly -- data recovery is possible from a damaged tape.
>
> >From bzip2's manual:
>
> bzip2 compresses files in blocks, usually 900kbytes long. Each
> block is handled independently. If a media or transmission error
> causes a multi-block .bz2 file to become damaged, it may be
> possible to recover data from the undamaged blocks in the file.
>
> The compressed representation of each block is delimited by a
> 48-bit pattern, which makes it possible to find the block
> boundaries with reasonable certainty. Each block also carries
> its own 32-bit CRC, so damaged blocks can be distinguished from
> undamaged ones.
>
> With gzip and compress, in general, once a media error is encountered,
> the entire remainder of the file (tar or dump in our case) is
> unusable. This is why people generally shun gzip/compress for
> backups, unless it's done on a per-file basis to lessen the severity
> of errors. Of course, doing it on a per-file basis also lessens the
> effectiveness ofcompression. The only tradeoff with bzip2 is CPU
> time: it is more CPU-intensive than gzip or compress. However, when
> reliability of backups is at stake, that's a tradeoff I'm quite
> willing to take,
>
> In amanda, the configuration file seems to think that the user isn't
> smart enough to manually specify a compression program :-) I'd much
> rather specify "gzip -9" and "gunzip" than specify "best compression"
> or whatnot. Are there any plans to support this? If there were, it
> would be trivial to drop in bzip2 instead of gzip with amanda.
>
> Are there any plans to support this? I suppose I could just go into
> the code with sed and s/gzip/bzip2/ but I'd prefer to do it more
> elegantly if possible :-)
>
> -- John
>
>
--
-
Richard Bond ([EMAIL PROTECTED] (206) 605-3561
System Administrator K-351, Health Sciences Center
Department of Molecular Biotechnology Box 357730
University of Washington Seattle, WA 98195
