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@msil.sps.mot.com

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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