[Veritas-bu] Duplication question
Heathe Kyle Yeakley
hkyeakley at gmail.com
Tue Dec 8 09:48:07 CST 2009
Let me explain *why* I'm trying to do this and maybe someone will have a
different approach to solve the same problem.
I'm trying to deploy a NetApp Virtual Tape Library. I have three
objectives for the deployment:
* My RPO is between 24 and 48 hours. I vault every weekday to get last
night's tapes out.
* I'd like to shrink my backup window. Therefore I'd like to present
dozens of virtual drives to NetBackup so that I can perform multiple
* I'd like to utilize my tapes as best as possible.
When I originally rolled out the VTL, I presented 80 drives to
NetBackup. This was on a Friday. When I came in Monday all my backups
had completed successfully. I ran Vault and the eject phase triggered
the Direct Tape Creation on the VTL. I watched all of this go by quite
smoothly. But then I got to counting how many tapes had been created and
noticed it was 30% - 40% more tapes than I normally write to over the
weekend. I thought about it for a bit and realized that what had
happened is with 80 drives, NetBackup grabbed 80 scratch tapes and
therefore didn't reuse any tapes. So I was ejecting 80 tapes that were
anywhere from 15% - 30% full.
I've rolled the VTL back into development. In my original configuration,
I met the 24-48 hour RPO and I shrank my backup window, but at the
expense of burning through a lot of tapes. I e-mailed Symantec to ask if
there is a setting in Vault where NetBackup will leave a tape in the
library if it's under X% full. I'm told there is not such feature, but
that it gets requested frequently.
On a side note, if you want that feature, I've submitted a suggestion on
the NetBackup suggestion page. Please vote:
Anyway, so I took the VTL back to the drawing board. My second thought
was to just present 12 drives to NetBackup since I'm making due with 12
physical drives right now. Only presenting 12 drives and thus only
backing up 12 clients at a time would reuse tapes and let me use my
media more efficiently. I could vault every morning to meet my RPO, but
12 drives really doesn't buy me anything in the backup window.
My next thought was to leave my dozens of drives presented to Netbackup
and just change my vault window from:
30 days ago to 18 hours ago
30 days ago to 5 days ago.
This would leave my tapes in the VTL for a few days to build up some
images on them. So I'm making good use of my media and I've shrunk my
backup window, but I'm putting my RPO at risk. If a fire or something
destroyed my datacenter, I've now lost a week's worth of data instead of
24-48 hours worth.
So now my current thought goes something like this:
1) Have two virtual libraries on my VTL.
- One library that does not employ DTC and has completely made
up barcodes (fred001, fred002... whatever). This library has dozens of
drives. We'll call this Vlib-A
- One library has Direct Tape Creation enabled and has virtual
tapes with a one-to-one relationship to the actual labels on the
physical tapes in my physical library. This library only has like 12 -
20 drives. We'll call this Vlib-B.
2) On Vlib-A, present dozens of drives to NetBackup and perform all my
backups. (This shrinks my backup window).
3) In the morning, duplicate all of last night's backups from Vlib-A to
Vlib-B. I've never used the Duplication feature in Vault, but I am
*assuming* that if I've got a library of say, 50 drives trying to
duplicate all of it's images to a library with say, 12 drives, that you
end up with more images per tapes on the receiving library. Once I
duplicate all my images from Vlib-A to Vlib-B, I'll use vault to eject
all the volumes in Vlib-B. The NetApp VTL will receive the eject request
and begin writing the contents of the virtual tapes out to physical tapes.
4) But now I have all these original images on Vlib-A that have been
duplicated and written to tapes on Vlib-B. If there was a way I could
erase successfully copied images as they are duplicated from Vlib-A to
Vlib-B, I could have a sort of "static" pool of tapes in Vlib-A that I'm
writing to every night, then duplicating off of every morning and then
recycling the tapes again for the next night's backups.
This configuration (while
WAAAAAAAAAAAAAAAAAAYYYYYYYYYYYYYYYYYYYYYYYYYYYY convoluted) would meet
all three of my VTL objectives. But my concern is that there's no way to
configure NetBackup to duplicate an image from TapeA to TapeB and then
automatically expire the images on TapeA so that TapeA is reused again
tonight. I'm afraid I'd have to come in and manually expire all the
images by hand using bpexpdate after ensuring that the images were
successfully copied to Vlib-B.
Anyway, that's what I'm trying to do. I've come up with half a dozen
ways I can have 2 out of 3 things on my list of objectives, but I can't
figure out how to have all three.
- Heathe Kyle Yeakley
On 12/08/2009 08:50 AM, Ed Wilts wrote:
> On Tue, Dec 8, 2009 at 8:17 AM, Heathe Kyle Yeakley
> <hkyeakley at gmail.com <mailto:hkyeakley at gmail.com>> wrote:
> I'm not sure if this is possible, but is NetBackup Vault
> capable of:
> * taking a backup image on tape ABC123
> * duplicating the image to some other volume (say ABC124)
> * promoting the copy on ABC124 to primary
> * automatically deleting the original backup on ABC123 so that my only
> copy is the primary copy on ABC124
> I know how to do the first three bullet points in Vault. It's that 4th
> one that I'm stumped on. I don't even know if it's possible.
> Just expire the images that are on ABC123 using bpexpdate -copy
> The key thing to remember is that NetBackup doesn't like to manipulate
> tapes - it likes to manipulate images.
> Ed Wilts, RHCE, BCFP, BCSD, SCSP, SCSE
> ewilts at ewilts.org <mailto:ewilts at ewilts.org>
> Contact Me Linkedin <http://www.linkedin.com/in/ewilts>
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the Veritas-bu