Paul,
I read about what I think you mean by "out of the back end duplication".
If I have it right, with certain subsystems you can run FC from the disk
straight to the tape library. The VTL is smart enough to know how to
duplicate images to the tapes. I guess the only thing I don't understand
is where NetBackup comes into play with that piece. Does NetBackup
somehow control the duplication process even though the data isn't going
through a media server? What I would want to avoid is using some other
software program to managed the duplication from the VTL to live tape
library.
As for the separate connection to the VTL, in our Windows environment we
currently have two FC cards in each SAN attached box. We have two disk
SAN's and connect one card to each for failover (Securepath). Currently
we just allocate tape devices through these two cards. For Windows, we
do not have a separate SAN for just tape. I know this would probably be
the best bet, but with the limited number of PCI card slots in most
newer servers, using 3 for FC cards just isn't possible.
I thought of one more question. Has anyone used VTL with NT 4.0? I know
it's a dieing breed, but not everyone is up to Win2k just yet.
Thanks,
Kris
-----Original Message-----
From: Paul Gimpelev [mailto:paulg AT CDCNA DOT COM]
Sent: Thursday, January 27, 2005 9:50 PM
To: Williams, Kristopher L; List Veritas List
Subject: Re: [Veritas-bu] Virtual Tape Library / Drives
Kris,
Your general understanding of how VTL works is pretty much
correct.
There are certain advantages to VTL which you have not mentioned such
as "out of the back end duplication" but if you need to keep an image
on-site as well as physical tape off site at the same time then you got
it. As far as whether to make any SAN attached host a media server
depends entirely on your configuration and what you need to back up off
of these hosts. If the amount of data is trivial, then it may be more
efficient to back them up over the network. You also need to consider
that VTL, just as a physical tape library, would require a separate SAN
connection(s) for the tape drive(s) apart from your existing SAN
connections to the disks.
Depending on your configuration, you might consider using fewer
robotics contorol hosts (you can have different drives in a single robot
attached to multiple hosts). In our scenario it works great because we
a)use centralized duplication and b)have clusered robotics control hosts
so our chances of having a downed robot is very low.
Again, it all depends on what you are tring to do, what you
currently have and how much you are willing to spend.
paulg
Save On Jan 27, 8:33pm, Williams, Kristopher L wrote:
> Subject: [Veritas-bu] Virtual Tape Library / Drives Hello all,
>
>
> I'm trying to get my head around exactly what and how a virtual tape
> drive system works.
>
> Here is how I see it: VTL is mostly a software product that allows me
to
> create virtual libraries and tape devices. I can then present those
> devices to any host connected to the FC SAN. (I know that some offer
> iSCSI but I only want to deal with Fiber in my example). Those virtual
> tape drives get written to by NetBackup just like normal tape drives,
> but the data really is stored on a central disk subsystem. Using NB
> duplication, I can get the data off to real tapes to be vaulted for DR
> purposes.
>
> I guess the first idea that comes to mind is to place a virtual drive
on
> every SAN attached host and make them all SAN media managers (I know
> that Veritas License Cost will make this sound crazy). I could then
have
> each SAN Media server write it's own data to it's local "Virtual" tape
> drive.
>
> Can someone who has a VTL system fill in the holes for me? I'm sure
> there are many many more considerations but I'm just at the thinking
> phase.
>
>
> Thanks,
>
> Kris
>
> _______________________________________________
> Veritas-bu maillist - Veritas-bu AT mailman.eng.auburn DOT edu
> http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
>-- End of excerpt from Williams, Kristopher L
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