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Re: [Veritas-bu] How to get capacity or type of tape media
2008-05-14 12:42:40
Thank you all for your responses. They have been most helpful.
I am intending to create a script that determines used and free raw capacity.
I have basically resolved to the fact that I will have to create some kind of look up that is specifically defined for the system I am running it on. IE: HCART2 = LTO2 = 200GB RAW something to this effect.
I appreciate all the responses.
Regards,
Kevin
On Tue, May 13, 2008 at 6:58 PM, A Darren Dunham < ddunham AT taos DOT com> wrote:
On Tue, May 13, 2008 at 04:15:33PM -0500, Kevin Miele wrote:
> All,
> I am trying to figure out how I can get the capacity or type of tape media
> from NetBackup. I don't see anywhere where I can get Raw Capacity of a tape,
> but see that bpmedialist does show density. The problem is that I am seeing
> hcart instead of DLT or LTO, etc.... I have also tried vmquery -a, but that
> doesn't show me enough detail.
>
> Is there anyway to get the actual raw capacity or actual media type from
> NetBackup?
and get an answer. (Think of an older 9-track drive that has a spool
with a random length of tape on it. It can't know how long it is).
Modern drives probably really *do* have that information in some form,
but there's no vendor-independent way to get the information, and it's
not certain how useful it would be (since it would relate to length of
media, not data capacity). I once saw an exabyte tool that would
display the percentage of tape that had been moved past the head on a
mammoth drive. But didn't have any way of using that tool unattended.
So netbackup and all the other commercial applications I'm aware of
don't even try to ask the question. They just deal with tapes that will
accept some amount of data, then declare themselves full.
The netbackup "density" field doesn't give you real information about
the physical tape's density either. HCART, HCART2, HCART3, etc. are
just labels to keep drives and tapes in groups that should work together
properly. HCART2 doesn't imply LTO2. It's least confusing if it's set
up that way, but that's up to the admin. NetBackup isn't enforcing this
mapping.
If I bring in a LTO2 tape as type HCART3 so I can use it with my
LTO3/HCART3 drives, NBU will have no clue that it has about half the
capacity of LTO3 tapes. And that's before any further affects like
compression and bad block rewriting.
--
Darren
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