ADSM-L

Re: Backup of Backup Tape

1999-04-19 14:08:52
Subject: Re: Backup of Backup Tape
From: "Prather, Wanda" <PrathW1 AT CENTRAL.SSD.JHUAPL DOT EDU>
Date: Mon, 19 Apr 1999 14:08:52 -0400
If it is convenient for you to use 8mm as your copy pool that's fine.
What many people do is use the same media (3570) for offsite as for onsite,
if you have a tape robot.
What I do is have an admin schedule that starts the copy in the wee hours so
that it is done when the operators arrive in the am.
Then we eject the tape from the robot and send it offsite, and mark it as
"offsite".
That way ADSM knows not to try and mount it anymore.

What you do is define a copy pool, then all you have to do is enter the
command :BACKUP STGPOOL primarypoolname copypoolname, and ADSM will create
all the copies for you.

If the 3570 (onsite) tape is damaged, all you have to do is:
*       Run a RESTORE command with PREVIEW=YES  (This will tell you which
offiste volumes you need to rebuild the onsite tape.)
*       retrieve the 8mm tape(s)
*       Run the RESTORE command again
ADSM will pull files off the 8mm tape, and write them back into the onsite
(primary) pool and mark the original 3570 as "destroyed".

If the primary tapes gets reclaimed, it doesn't affect the copy pool tape.
The copy pool tape isn't an image of the primary tape - backup stgpool is a
file-by-file copy, not a tape image copy.
When the primary tape is reclaimed, ADSM just updates all the data base
pointers.
The files in the primary pool are now on a different tape, but the versions
in the copy pool are still on the same copy pool tape.

If this isn't clear, let me know....
************************************************************************
Wanda Prather
The Johns Hopkins Applied Physics Lab
443-778-8769
wanda_prather AT jhuapl DOT edu

"Intelligence has much less practical application than you'd think" -
Scott Adams/Dilbert
************************************************************************






> -----Original Message-----
> From: Dennis Knee [SMTP:dknee AT NAZARENE DOT ORG]
> Sent: Monday, April 19, 1999 12:11 PM
> To:   ADSM-L AT VM.MARIST DOT EDU
> Subject:      Backup of Backup Tape
>
> How do I go about getting my adsm tapes backed up. Do I copy from say a
> 3570 vol to say an 8mm vol, and then mark the 8mm as offsite?
>
> If I need to access the 8mm copy in case something happens to the 3570,
> do I just add the volume back, and copy it back to another 3570 vol?
>
> What if a 3570 vol that has already been backed up becomes eligible for
> reclamation?
>
> I apologize if this is too elementary.
>
> Thank you,
> --
> Dennis Knee
> Information Technology
> Church of the Nazarene
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