Veritas-bu

[Veritas-bu] Plans for LTO-1 to LTO-2 conversion

2004-05-28 16:21:54
Subject: [Veritas-bu] Plans for LTO-1 to LTO-2 conversion
From: Mark.Donaldson AT cexp DOT com (Mark.Donaldson AT cexp DOT com)
Date: Fri, 28 May 2004 14:21:54 -0600
Yeah - I saw this as an option - freezing all the current tapes, but there's
1000+ tapes of storage capacity we're just not ready to abandon yet.  Our
comparitive short-retention cycle would make these LTO1 tapes become
obselete quickly, otherwise I'd go with the HCART2 option and just use the
older LTO1 stuff for long-term images.  We don't have enough of those
compared with the overall on-tape image sets.

Anybody have problems getting an LTO2 drive recognizing an LTO1 tape &
appropriately dumbing itself down - or the reverse, I guess, not having an
LTO2 drive recognize a new LTO2 tape as the higher density & speed?

-----Original Message-----
From: La Manna, Joe [mailto:joe.lamanna AT citigroup DOT com]
Sent: Friday, May 28, 2004 10:30 AM
To: Mark.Donaldson AT cexp DOT com; veritas-bu AT mailman.eng.auburn DOT edu
Subject: RE: [Veritas-bu] Plans for LTO-1 to LTO-2 conversion



Mark,

Whenever we have done similiar drive refreshes, we keep the drive "type"
the same but  set max mounts on and freeze the existing tapes so that they
can be mounted for restores but won't be written to. This forces new
media to be used.  It costs you more in media up front but was the safest
way to go - we had read different things regarding possibly overwriting
tapes or that in order to get the new density, the tapes had to be labelled
by the new drives, etc....



Joe


-----Original Message-----
From: veritas-bu-admin AT mailman.eng.auburn DOT edu
[mailto:veritas-bu-admin AT mailman.eng.auburn DOT edu]On Behalf Of
Mark.Donaldson AT cexp DOT com
Sent: Friday, May 28, 2004 12:10 PM
To: veritas-bu AT mailman.eng.auburn DOT edu
Subject: [Veritas-bu] Plans for LTO-1 to LTO-2 conversion


Lemme run this past you all and see if you can see holes in this plan.

We've got a 1000+ LTO-1 tapes in a library with a bunch of LTO-1 drives.
Nice, right?

Nope - there's a plan to convert the whole mess to LTO-2, abandoning the
LTO-1 drives but not the LTO-1 tapes.

HCART1 & HCART2, right?  Well, no.  We want to keep using the LTO-1 tapes in
the (supposedly backward-compatible) LTO-2 drives.

So, here's the plan:  

Put the LTO-2 drives into the library as HCART drives (just like our current
LTO-1 drives).  DO NOT add any LTO2 media until all the LTO-1 drives are
removed.  This will keep the LTO2 tape from being used by an LTO1 drive.

Only when all drives are replaced with LTO2 do we add any LTO2 media (also
as HCART media - same as our LTO1).  The plan is to use the auto-sensing
technology in the drives.  If an older LTO1 tape is mounted in the LTO-2
drive, we plan that the drive will dumb-down to LTO-1 to read and write.  If
the LTO-2 drive gets a newer LTO-2 tape, we plan that it'll write at LTO-2
densities and speeds.  Over time, we'll transition all the LTO1 media out
and replace it with LTO2 media (we're really after the speed and not the
density benefits of LTO2).

So - this hinges pretty heavily on the ability of the drive to auto-sense
the tape type and change its behavior - a feature I'm pretty sketchy on.

Comments?
-M

=================================================
  There are 10 kinds of people in the world,
  those that know binary, and those that don't.
=================================================
  Mark Donaldson - SA - Corporate Express
=================================================
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