SUGGESTED SOLUTION(s):
1) Use tprobe; Find via Archie; can ftp from internet host archives including:
   192.48.96.9	ftp.uu.net		     /usenet/comp.sources.3b1/volume02
   128.146.8.52	archive.cis.ohio-state.edu	/pub/comp.sources.3b1/volume02
2) Use copytape; Find via Archie; can ftp from internet host archives including:
   192.48.96.9	ftp.uu.net	/usenet/comp.sources.unix/volume10
   128.218.1.13 ccb.ucsf.edu	/Comp.sources.unix/Volume10
   129.173.4.5	cs.dal.ca	/pub/comp.sys.sun/volume10
3) Use tcopy; % man tcopy (1)
4) Use "our tape duplication process shell script" or "my C program".
5) Use dd with the following options, et. al.; Or don't/why make copies at all.
> dd if=/dev/nrst0 of=/dev/nrst1 bs=126b
> 
> Of course, this would need to be in a loop to process all the dump file
> son the tape. The block size should be the same as used for the dump
> command, 126 blocks (63k) is typical and the recommended value.
> You definitely _do_not_want_ conv=sync as this will pad blocks, ie add
> extra bytes into the file(s). You shouldn't need any conv options. Also
> 
> Don't do conv=noerr, because that will ignore read errors in the copy.
> Also, you should add obs=blocksize.
> 
> Why would you make copies in the first place? The mechanism I use is
> much easier:
> - Once a week, I made a complete backup set that would allow me to rebuild
>   from scratch if it ever becomes neccessary
>   (colleagues needed those some weeks ago because a strike would not allow
>   anyone on the place their computers were and they had to move to another
>   spot. So, backups are a good idea)
> - The fresh newest backup set remains on-site that week for uncareful users;
> - The next older one goes to the off-site spot.
> - NEXT DAY, the older-older set comes back from that spot (so there is 
>   *always* at least one copy off-site)
> - Then copies wait a few weeks until they are re-cycled. After a few cycles,
>   they are archived. I have one archive copy per month.
> 
> That is a much better approach, IMHO. Much less work.
> 
THANKS TO:						FOR REFERENCE TO:
Nico Garcia		<raoul@athena.mit.edu>			tprobe
Phil Blanchfield	<phil@dgbt.doc.ca>			copytape
Koper Zangocyan		<cc_koper@rcvie.co.at>			copytape
Mike Raffety		<miker@il.us.swissbank.com>		tcopy (1)
Henry Katz		<hkatz@nucmed.med.nyu.edu>		tcopy (1)
Andy Toy		<andy@mks.com>				tcopy (1)
Steve Vu		<svu@esri.com>				tcopy (1)
John P. Linderman	<jpl@allegra.att.com>			tcopy (1),et.al.
Javier Santos		<jms@jericho.mc.com>			own sh script
Piete Brooks		<Piete.Brooks@cl.cam.ac.uk>		own C program
Glenn Satchell		<glenn%ups.uucp@fourx.Aus.Sun.COM>	dd (1), et. al.
Geert Jan de Groot	<geertj@ica.philips.nl>			dd (1),mechanism
ORIGINAL QUERY:
--- Forwarded mail from espiritu@cgi.com (Rex Espiritu)
>From espiritu Mon Mar 29 14:46:37 1993
>From sun-managers-relay@ra.mcs.anl.gov Tue Mar 30 03:56:15 1993
Sender: sun-managers-relay@ra.mcs.anl.gov
>From: espiritu@cgi.com (Rex Espiritu)
Reply-To: espiritu@cgi.com (Rex Espiritu)
Followup-To: junk
To: Sun Managers Mailing List <sun-managers@eecs.nwu.edu>
Subject: WANTED: dd command to duplicate 8mm dump tape(s)
Cc: Rex Espiritu <espiritu@cgi.com>
Status: ORS
I'd like to make duplicate copies of 8mm dump tapes to keep the month end
backups on-site as well as archived off-site.  If anyone else does this on
a regular basis, I'd appreciate your sending me the exact dd command(s)
you use for comparison.  I'm particularly interested if any "conv" option
is desirable to use, e.g.:
        # dd if=/dev/nrst0 of=/dev/nrst1 conv=noerror,sync
Thanks in advance,
Rex
espiritu@cgi.com
-- M. Rex Espiritu, Jr. Carnegie Group, Inc. espiritu@cgi.com 5 PPG Place Voice: 412 642-6900 x233 FAX: -6906 Pittsburgh, PA 15222--- End of forwarded message from espiritu@cgi.com (Rex Espiritu)
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