In <[log in to unmask]> [log in to unmask] writes:

> Every week we do a "full" backup of our system (i.e. @[log in to unmask]@) which is fine and
> dandy. But they/I use 3600' reel to reel tapes at 6250 cpi. It takes apx 4.5
> hours and uses 16-18 tapes on average depending on what time of the year it
> is.
>
> Whereas every night besides the one night we do the full backup we/I do an
> incremantal backup of only the things that got changed since the last "full"
> backup. For this we use a 4mm 90m 2gig dds dat tape and it takes about 3
> hours to finish and only uses 1 dat tape no matter what time of the year it
> is.
>
> So the obvious question is :
>
> Why the HELL don't they use 2 dat's or 3 dat's or whatever it takes to do the
> full backup(s)??
>
> Is there some type of problem with the store command or the MPE version that
> won't support 2 or more dat's in sucession on a store or are they just giving
> me a line of bullshit and want me to suffer.

Sounds like a job-security issue. Full backups to DAT tapes work fine, but
ya don't need to pay an operator to mount 18+ tapes... Even basic MPE Store
can store to multi-dats; when one finishes, you pop it out and put in the
next one. Most of the third-party store packages can use multiple dat drives
concurrently, or backup what won't fit on tape to a temporary disc file, so
the system comes back online and someone pops in a final tape in the morning
and the backup job finishes copying the rest of the data (now in a temp disc
file) to tape while the system runs normally.

Back at a previous job, when we switched our 3000 from reel-tape backups to
DATs, we were able to eliminate a full operator shift... ;-)

We also eliminated a storeroom full of reel tapes, our off-site pickup serv-
ice (the dat tapes fit nicely in a $60/yr safety deposit box at a bank down
the street), cut our backup down-time to a fraction of what it was, and
greatly decreased our media costs (1 DDS @ about $12 vs 8-12 reels @ about $4).
We also generally had fewer tape i/o errors...

                 -Chris Bartram