| Anne & Lynn Wheeler 2006-10-30, 7:16 pm |
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glen herrmannsfeldt <gah@seniti.ugcs.caltech.edu> writes:
> The mmm is incremented. You need to supply one DD card
> for each file you expect to read. There is no requirement
> that they be on the same tape, or even on tape at all.
> One reason is the extra work to process standard labelled
> tapes. There are label records between files, in addition
> to the tape mark.
>
> VMS processes ANSI labelled tapes, and so may also do
> some of this processing. I did once convince OS/VS2
> to write an ANSI labelled tape to read on VAX/VMS.
standard label had 80-byte "VOL1" record (similar to what is used on
disk). files had 80-byte "HDR1" record (and sometimes "HDR2" records)
.... dating back to at least 360 days.
here is more discussion (from quicky use of search engine) for "VOL1"
and "HDR1"
http://it-dep-fio-ds.web.cern.ch/it...ive/labels.html
above also discusses ansi x3.27 standard and dec systems use.
some of the current tape library software managing later generations
of large capacity tapes do volume stacking ... where a single physical
tape will contain images of multiple logical tape volumes.
search engine reference included volume stacking
http://publib.boulder.ibm.com/infoc...fmnu1e02233.htm
misc. other search engine URLs mentioning VOL1 and HDR1
http://www.vsoftsys.com/doc/doc42/vtape/vtap4006.htm
http://operations.rutgers.edu/tapes/tape_formats.html
http://www-03.ibm.com/servers/eserv...oads/tools.html
http://groups.google.com/group/alt....c76930d628ef0fa
http://www.decus.org/libcatalog/doc...l/vs0097_8.html
http://cnlart.web.cern.ch/cnlart/234/art_tlab.html
http://www.cbttape.org/awstape.htm
http://mitvma.mit.edu/cmshelp.cgi?CMS%20TAPEMAC%20(ALL
http://mitvma.mit.edu/cmshelp.cgi?CMS%20TAPPDS%20(ALL
http://pcmap.unizar.es/softlinux/VMS-to-Linux-HOWTO.txt
search engine even turns up one of my old pasts mentioning VOL1 and
HDR1:
http://www.garlic.com/~lynn/2004q.html#20 Systems software versus applications software definitions
which discusses an old backup/archive system that i had written for
internal use ... which then went thru several iterations and
eventually released as workstation datasave facility, morphed into
adsm and is now known as tsm
http://www.garlic.com/~lynn/subtopic.html#backup
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