Grant Melvin wrote the content below (thanks, Grant), and I thought
that I would forward to toasters.
David
Hi Philip,
> One of our groups is evaluating NetApp for NFS server.
> Apparently, their backup concerns are not being satisfactorily addressed
> by local NetApp contact. Since backup is a key factor in their
> decision, they would appreciate if someone could shed some more
> light to their following questions/concerns.
> Please feel free to copy the group at:
> mannyk(a)msil.sps.mot.com
> ---------------------------------------------------
> It seems that they have a few select tape drives
> that are now able to be connected to the netapps and are recognized
> by netbackup.
>
> The problem I still see and have not recieved a clear answer to is
> will ndmp support the tar protocol or just dump?
>
Today NDMP as implemented on the NetApp filer only offers
dump format, since this is the only backup method natively
available on the filer.
However, once the filer has other backup formats available,
they will be accessible via NDMP. We are in discussion with
many backup vendors to determine the best way to add support
for their favorite data format and we are ensuring that the
NDMP infrastructure is correct in offering these other formats.
We also have been working on a new internal NetApp format that
will
be made available via NDMP.
So the question is not will NDMP support the tar protocol, but
when. The answer to this involves the cooperation of the backup
vendors who use tar.
>
> Does the ndmp protocol support the full dump command -
> different levels of dump (incremental, differential and full)?
>
Yes. My understanding of incremental, differential and full is:
full = level 0
incremental = last level + 1
differential = level 1 followed by level 1 (each backup grows)
>
> When and if we will be able to hook up several netapps to one
> large tape library unit (STK 9710)?
>
This can be done today given that your backup vendor software
supports the STK 9710. NDMP allows the backup s/w such as
netbackup
to control the library via SCSI-2 and to perform "local" tape
backup on each attached tape drive. In the case of the 9710, 10
volumes or 10 filers simultaneously backing up to one library.
Note, we have a current limit of 4 dumps per filer.
I'd suspect that Veritas havn't QA'd such a configuration yet
and have simply stuck with the minimum NetApp supported devices
for their current (beta) release.
*** Currently, Veritas is sticking to just the NetApp supported devices
but this may change. There is a mutual interest in expanding the
set of supported devices, but certification process details need
to be worked out. - David
>
> What in the ndmp protocol will allow several backup streams
> to work simultaneously, so that a full backup of an 800 GB
> netapps won't span over several days.
>
There is nothing in NDMP other than allowing multiple
dumps to occur on a single filer. We are planning to have
our next software release allow quota trees to be dumped so
they data can be split into several dumps or you can use 5.0
today and have separate volumes dumped concurrently. The big
thing is performance of each individual dump. We have an
increase in performance with 5.0 -- our testing has shown two
volumes dumping at an aggregate of 23GB/hr and 1 dump running
at 15GB/hr. We have still to quantify 4 dumps, however, our goal
in the next release is to have a 20GB/hr dump which will
definitely help your backup window above.
If we could achieve 4 x 20GB/hr dumps to backup your 800GB
in ~10 hours we would be very pleased. We'll keep you
informed of our progress.
Let me know if you need anymore information.
Cheers,
Grant