Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!cs.utexas.edu!sm.unisys.com!hplabs!hpda!hpcuhb!hpcilzb!hpcea!hpbsla!campbell
From: campbell@hpbsla.HP.COM (gary campbell)
Newsgroups: comp.sys.ibm.pc
Subject: Re: ARC Wars
Message-ID: <360004@hpbsla.HP.COM>
Date: 13 Sep 88 17:17:53 GMT
References: <1653@dataio.Data-IO.COM>
Organization: Hewlett-Packard Boise R & D Lab
Lines: 42

>By the way, for those people who are designing new arc formats, here's things
>I'd like to see that nobody ever talks about:

I would like an archiver with compression that can handle multi-floppy
archives, primarily as a means of system backup.  I have never heard of
a freeware offering addressing system backup.  This surprises me a bit,
with all of the horror stories about backup/ restore floating around.
(Is this because noone wants to trust their system backup to a freeware
product :-)?)

Zoo, with its data compression and its ability to store subdirectories
looks like a possibility, but there is the problem of handling multiple
floppy backups.  The PD Tar just distributed will handle multi-floppy
backups, but doesn't compress, at least not on the PC.

First, do you know of any existing freeware solution to this problem?
It seems like it shouldn't be too hard to add an option to Zoo, either
to sense the available room on a floppy, or to supply a maximum archive
section size.  I don't know the format of a Zoo file, but I assume that
there is or could be a header identifier to identify continuations of an
archive.  I haven't decided whether such a thing should be able to break
a file between disks, allowing processing of a file which compresses to
a size that is larger than a floppy, or whether to force a file to fit
on a floppy.  What does Backup do?  I think it should be possible to
list and extract files from any volume of the archive without having to
read the whole archive, and it would be nice to be able to get a
complete listing from the first volume along with volume number.  This
latter might be better done with a log file.

Someone on a local BBS made the following comments about compression in
a backup utility:  "Also, you would have to wonder about the integrity
of the backed-up files.  If the archive dropped one bit -- it could
destroy multiple files within the one archive.".  I think that Zoo
compresses each file separately, so the part about losing many files
wouldn't be true, but is his other concern valid?

I am interested in any comments or suggestions you may have on this
subject.

--
Gary Campbell
{decvax,fortune}hplabs!hpbsla!campbell