topic Re: Tape Save sets with /block=65535 in Operating System - OpenVMS

Tape Save sets with /block=65535

Nigel Wright_1 — Thu, 18 Sep 2003 08:56:42 GMT

With tape Save sets with /block=65535 it is not possible to do a mount/over=id then a copy of the save set to disk. Does anyone know a way around this?

Re: Tape Save sets with /block=65535

Ian Miller. — Thu, 18 Sep 2003 09:32:47 GMT

hp Save Set Manager product is the thing to use for this sort of thing

Re: Tape Save sets with /block=65535

Dieter Rossbach — Thu, 18 Sep 2003 10:41:48 GMT

The reason is: RMS maximum block size for disk operations. Write your savesets with /block=32000 and cou can copy them from tape to disk. BTW: /block=32000 results in a resonable blocksize of 32256

Dieter

Re: Tape Save sets with /block=65535

Martin P.J. Zinser — Thu, 18 Sep 2003 13:19:40 GMT

But the /block=65535 is there for a reason ;-)
Having a large block size is an important performance enhancement for todays tape drives.
So there is a trade-off between backup speed and the need to copy complete savesets to disk. What we do in our environment is to have a few days of backup-data parallel on disk (which does eliminate the need for most tape restores) and keep the large blocksize for the tape backup.

Re: Tape Save sets with /block=65535

Nigel Wright_1 — Thu, 18 Sep 2003 13:27:43 GMT

Thanks for all the comments so far. I understand the problem but I need to move these save sets from one tape to another. But due to the large block size I am having to explode them to disk (thus re-creating the dir + files), then create a disk save set, then finally copy them to tape.

Re: Tape Save sets with /block=65535

Hein van den Heuvel — Fri, 19 Sep 2003 02:39:12 GMT

Ayup, 'exploding the saveset, and re-packing may be the way to go.

However, if your real problem is to copy tape-to-tape then there are [freeware] tools to achive that. For example 'tapecopy'. [note, I have never tried to use this tool]
http://h71000.www7.hp.com/freeware/freeware50/tapecopy/

http://h71000.www7.hp.com/freeware/freeware50/FREEWARE/00FREEWARE_ABSTRACT.TXT

Be sure to check otu the Polycenter SSM (save set manager) suggestion. That's supposed to work.

Re: Tape Save sets with /block=65535

Rick Dyson — Fri, 19 Sep 2003 13:11:55 GMT

I had a similar problem and just wanted to
'clone' backup tapes without two-stepping it.

I found a freeware utility (TAPECOPY) that
has worked just fine for me on Alpha v7.2 and
VAX v6.2 for DLTs and DATs. The version of
TAPECOPY I got was a MACRO from early 2000
and it needed to be updated to compile on an
Alpha. It sort of looks like it was originally
written in 1990 for a VAX.

NOTE: Except for the SLS package, there is
apparently no other way to make a simple tape
clone. I.e., $ Copy MKA100: MKA200: won't
work when they are foreign.

Let me know if the freeware version pointed to
in the previous reply is still the old kit.

Rick

Re: Tape Save sets with /block=65535

Ian Miller. — Mon, 22 Sep 2003 10:34:58 GMT

the freeware referenced in the earlier reply does appear to be the macro-32 from 1990.