On Tue, Jun 26, 2001 at 08:01:18AM -0700, Lance R Bailey wrote:

because of this ... feature... you now have to include vendor hardware in your disastor recovery plan. it is not hard to rationalize that if you think it prudent to keep your backup tapes offsite, then you should also keep a filer offsite. how good are your tapes if you cannot

Isn't this logic necessary? One usually keeps tapes off-site in case of a "catastrophic failure" at your place of business. If your data center burns down, even tapes with fabled cross-platform backup formats will be useless unless you have replacement equipment. Paying for off-site tapes without paying for near-line backup computing and facilities is a bit of a waste, no?

recover from them without specific filer hardware? how fast can your vendor supply you a replacement head? you might not be using that vendor anymore. 10 years ago (and i have recently pulled from tapes that old) almost noone was using filers. will we be using them in another 10 - or will we need to run to "bob's house of old computer bits" to find a filer that allows us to recover our data.

This is an over-dramaticism of the situation. We've run filers since F300 series and bought just about every model in between. We often restore and backup between different head architectures with absolutely no problem. The problem is that if you want to get all UNIX permissions and NTFS permissions out of any NetApp format dump stream (yes, this applies to non-NDMP backups created with ONTAP "dump"), you need a machine running ONTAP.

further, i have had troubles with using NDMP between different versions of OnTap. this means that i must maintain multiple vendor hardware.

for example, i have had problems with, and was told by netapp, that 6.X OnTap cannot neccessarily use the restore_symboltable from a 5.X machine. so... if i have a 5.X set of fulls and incrementals, i should keep not only a netapp that can run 6.X but one that can run 5.X - now that is easy with a 600 or 700 series, but when 7.X comes out...

I'm not going to endorse the validity of this since we've never had such a problem using sets of full and incremental dumps made with the same version of ONTAP getting restored on a different version with *any* of their H/W platforms. The same is true of other NAS vendors running NDMP.

However, NetApp does not tend to be very faithful to standards in their CLI command set, CLI output, configuration file formats, and backwards compatibility. Because they are willing to change such things rather quickly between major ONTAP rev's, the situation could (and may have already) arise where a backup set is un-restoreable in a newer version of ONTAP. Other NAS vendors may also do this and it certainly can be a pain in the butt. I'm in *total* agreement that this shouldn't happen.

• the media
• something that accepts the media
• s/w that can read the media
• a place to put the data read from media

I don't disagree with that, but I argue that it is all thats necessary with NDMP. You need the media, the transport (tape drive) to put it in, ONTAP to read the dump format, and a disk to put it on.

Note that your problems seem to be more with the fact that varying NAS vendors have different backup formats. This is probably not going to change anytime soon. Different OS's have different filesystems for the express purpose of competition - they offer different features over one another. As long as filesystems contain different kind of meta-data they will require different kinds of backup formats. I challenge you to pull any data out of a set of Oracle backups without an instance of Oracle running. The only difference is that with NAS boxes, they generally only write their OS for some proprietary hardware. Databases and other complicated filesystems may be able to run on different h/w platforms, but you'll find the choices end up being just as limited.

To be honest, I don't want an interchangeable backup format. I like that the NetApp dump stream can encapsulate data about qtree's which may not be a feature of other NAS boxes. I wouldn't want to only backup the least common feature set - that would be rather limiting. What if JeffCo. (fictitious) created their JeffNAS 2000 box that could store crazy meta-data such as the contact person for each file/directory, or the planetary alignment at file creation? If we just tar'd it up we'd loose all that valuable data! =)

As Grant said in his mail, NDMP is just the plumbing.

And in response to whomever said "NDMP isn't an enterprise backup/restore solution", I obviously take issue with that. We've got a warehouse of DLT tapes with several years worth of backups spanning around 50 filers and a few locations world-wide. It works fine.

-- Jeff

-- ---------------------------------------------------------------------------- Jeff Krueger, NetApp CA E-Mail: jeff@qualcomm.com Senior Engineer Phone: 858-651-6709 Storage Lead (NAS/SAN) Fax: 858-651-6627 QUALCOMM, Inc. IT Engineering Web: www.qualcomm.com