[Info-vax] Backup TK50 tapes

[Johnny Billquist]

On 2013-02-23 16:47, Stephen Hoffman wrote:
> On 2013-02-23 15:16:11 +0000, supervinx said:
>
>> Before any misunderstanding will occur...
>> Together with a VAX4000/300 I rescued some original TK50 tapes.
>> They contain VMS 5.5, 5.5-1 and they seem not to contain any saveset,
>> but only
>> *.EXE files (VMB.EXE, SYSBOOT.EXE...) so they looks like bootable tapes.
>> Am I wrong?
>> Since I never installed VMS except from a CD, I'm dubious about boot
>> tapes.
>
>
> Presuming you have the necessary permission to replicate these files,
> you can MOUNT the magtapes Files-11 (not /FORIEGN), extract the OpenVMS
> VAX installation files — the .A, .B, .C, etc. saveset files that are
> after all the OpenVMS VAX baggage needed for a sequential OpenVMS VAX
> bootstrap — with DCL commands including COPY, and then transfer those
> files to the target system via LD, done.

I have not looked at how bootable tapes under VMS looks like, but if 
they are anything like under PDP-11, this would give you all the regular 
stuff, like the savesets, but it misses the boot blocks and related 
data, since that is not visible as a file on the ANSI tape format.

> Last time I did a dd with a tape — which was admittedly a very, very
> long time ago, as serious use of bootable tape media has been shunned
> for years — it didn't deal at all well with the differing block sizes,
> which caused all sorts of problems when replicating the media.   I don't
> know of an automatic tool to do that, other than rebuilding the kit as
> DEC VMS engineering once did, with the various tools in OpenVMS.

Right. dd just is the wrong tool. It's really easy to throw together 
your own small program to actually read blocks, and keep the block 
structure around. But no standard utility for this exists. (On Unix - as 
far as I know.)

By the way, if you have a current RSX system, there is a tool in there 
to do exactly this work.

	Johnny

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol