RE: Multiple backups on single tape?

["Andy Nolen-Parkhouse" <aparkhouse@xxxxxxxxx>]

Evan,

I would agree that multiple uses of a single tape for different saves
might provide some benefit.  My previous post was more in reaction to
Brian's assertion that Ghost was a model which IBM should examine.  With
the SAVSYS command (and SAVSTG as well), the system is creating a
bootable set of files which the machine expects to find beginning with
the first file on a Standard Label tape.  I would imagine that it would
be very non-trivial to somehow allow a system coming up with empty disk
drives to examine all loaded tapes for multiple copies of a SAVSYS
backup and then allow the user to select which one they would wish to
use.

The non-bootable saves all default to putting the files after the last
sequence number on the tape, so the problem we're referring to only
occurs on the SAVSYS.

On a partitioned machine, each partition is logically separate.  If you
have a single-slot tape drive which is shared between partitions then
yes, you would need to insert a new tape for the next partition when
doing a disaster recovery backup.  I would imagine that IBM will
continue to develop communications between partitions and the ability to
manage such machines conveniently.  While it may be somewhat
inconvenient, it strikes me as more convenient and more economical than
the alternative of maintaining separate hardware platforms.

Let IBM know what you want.  If I understand correctly, you would like
to be able to do an unattended full disaster recovery backup of all
partitions on a particular machine.  I can imagine some code which would
run at each console checking the status of the other 'machine'.  When
the first system comes up in non-dedicated mode, then the second system
could allocate the tape drive and start the save.  I don't see any way
to get around the problem of putting the SAVSYS at the start of a tape;
this would require a library device with multiple slots.

Regards,
Andy Nolen-Parkhouse

> Subject: RE: Multiple backups on single tape?
>
> Andy
>
> If I have a number of partitions, how do I create a SAVSYS for each of
> them
> ? Seems like being able to use a tape in the way that was suggested
might
> have some application in a multiple partition machine.
>
> Otherwise that expensive tape resource with extra capacity to backup
all
> my
> systems needs operator intervention when I'm doing a system save on
ANY of
> my partitions. Of course I probably do anyway as all system saves have
to
> happen interactively from the console. (not to mention having to have
a
> dedicated console connection for each partition)
>
>  From an application point of view this does make the system a little
hard
> to manage and needs a little more thought IMHO.
>
> Just another perspective.
>
> Regards
> Evan Harris