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From: Darren Reed <avalon@coombs.anu.edu.au>
Subject: Re: Dilemma. how to store DOS directories ?
To: mouse@Rodents.Montreal.QC.CA (der Mouse)
Date: Sat, 29 Mar 1997 15:09:28 +1100 (EDT)
Cc: cgd@cs.cmu.edu, darrenr@cyber.com.au, hackers@FreeBSD.org,
        port-i386@netbsd.org
In-Reply-To: <199703281337.IAA13593@Twig.Rodents.Montreal.QC.CA> from "der Mouse" at Mar 28, 97 08:37:19 am
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In some mail from der Mouse, sie said:
> 
> >>> Given that the various FAT formats aren't really related, it seems
> >>> like a bad idea to try to wedge them into normal 'restore' (or
> >>> 'dump,' for that matter).
> >> I wonder if gtar's facilities for doing incremental dumps aren't
> >> more suitable to dumping FAT file systems than dump is...
> 
> > I'm deliberately avoiding tar/cpio for the following reasons:
> 
> > * each writes individual files to tape (less efficient on some tape
> >   media, not to mention slower)
> 
> I have no clue what you're talking about here, at least with respect to
> tar.  A tar tape is a stream of 512-byte blocks, reblocked depending on
> the blocking factor, typically reblocked to 10K blocks.  This is true
> regardless of where file boundaries fall.

EOF markers being written to the tape, the lack of indexing and the resulting
"awkwardness" of its use.

If I recall correctly, on exabyte, EOF markers are "1MB" in size (although
newer tape formats aren't quite so braindead).  So more files on the tape
means less space for real data.  When ypu're backing up in excess of 100,000
files onto the one tape, it makes a difference.

Darren