BoxHill Systems Sells a set of scripts to do AFS backups to a
networker environment, including the use of DLT libraries.
While expensive, they seem to work just fine and allow us to
combine AFS and other backups in a cost effective manner.
John Allen
> From [EMAIL PROTECTED] Fri Feb 9 10:59:28 1996
> Date: 09 Feb 1996 10:20:49 +0100
> From: [EMAIL PROTECTED]
> Subject: Re: Use of DEC's DLT towers
> To: [EMAIL PROTECTED]
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>
> Dave
>
> We had a look at the DEC DLT towers for using them for Legato and AFS backup.
>
> After a detailed discusseion with one of the DEC guys in product
> support, we ame to the conclusion that it would be quite possible to
> combine the afs3.4 butc callout facilities and Legato Meda and Robot manager.
> But you have to be sensible aabout this and have realistic expectations.
>
> 1) dump is no problem, but one has to find a way to correlate AFS
> tape-labelling and numbering system with Legato's and the organisations
> external tape store
>
> 2) savedb ditto
>
>
>
> 3) readlabel cannnot easily be suported because the essence of the
> command is that one doesn't know the label of a given tape so how would
> one ask the robot to load the tape?
>
> 4) scan tape ditto
>
> 5) writelabel ditto
>
> 6) restoredb must also be a manual operation, you do this when you lost
> your AFS backup database, so who would know the ID of the Ubik_db_dump
> tape to load. This must be a manual operation (get the last Ubik_db_dump)
>
> 7) restore can after some work probably made to work if one first
> determines the tape needed and load them in the tower (probably
> ejecting other tapes)
>
>
> A tricky one and one that you want to work is appendump. Our
> incrementals are fairly short so we want to place several incrementals
> on one tape, but.....
> If you go through the motions you find that when the callout asks for
> appenddump so and so, you have to load the "the last tape used before
> for this series of incrementals" neither the ID passed to the callout
> on appendump, or the fact that others use the same drive since the last
> incremental, so "yesterday's" tape is not in the drive anymore, are helpfull
> Since all problems in IT are solved by adding one additional layer of
> indirection, that what I think is necessary. During a series of
> incrementals, maintain a list of tape-ids (Legato's media managar
> id"s?) used and from that list load the last. If you lose this list
> every now and then is not a real problem as AFS backup's appenddump
> would be happy with a fresh tape in that case. You need to register the
> fact for later restores.
>
> So we will, after we have organised ourselves after the
> re-organisation, first try a single drive DLT and then a robot. Only
> when it have proven it works, we will purchase one.
>
>
> Have fun
>
> Joop Verdoes
>
>
