Lance:

I don't agree full with your argument. First of all, when changing backup/restore platforms, be that the machine being backed up, the tool backing it up, or the medium backed up to, you must put in place a procedure for legacy restores. If part a requirement of your legacy restore plan is that you need to keep one of that OS, tool, or tape drive around, then you have to keep it around. That's why we have a BudTool server, a machine running Novell NetWare, and a whole host of old, weathered tape drives. =)

On the other hand, I agree with you that it would be nice if all new technologies were fully backwards compatible. It would also be nice if all technology was cross-vendor compatible. Unfortunately, reality dictates that for new functionality to be implemented, backwards compatibility sometimes has to be sacrificed, just as fostering competition among vendors requires differentiation and hence, fairly incompatible systems.

Technically, what you are asking for is impossible at this stage of the game anyhow. NDMP is a great and flexible protocol, but it only serves as a conduit for pushing back and forth big data streams. The host that generates the data stream defines the format of outgoing streams and what it can read from incoming streams. For NetApp, the stream it reads and writes is ONTAP native dump format. The only way you could restore a NetApp NDMP dump to some other vendor's product which supports NDMP is if that vendor also supports and understands how to deal with a NetApp dump stream.

Veritas cannot guarantee this in any way. NetBackup only knows that it wrote a big long stream of blocks to tape, and it receives a chunk of file history aimed at helping us humans figure out what files are in there. NetBackup doesn't know if that long stream of blocks was NetApp dump format, tar format, cpio, or otherwise. In NDMP, it is the responsibility of the data servers themselves to write and read blocks in the way they feel most comfortable.

-- Jeff

-- ---------------------------------------------------------------------------- Jeff Krueger, NetApp CA E-Mail: jeff@qualcomm.com Senior Engineer Phone: 858-651-6709 NetApp Filers / UNIX Infrastructure Fax: 858-651-6627 QUALCOMM, Inc. IT Engineering Web: www.qualcomm.com

On Fri, Apr 20, 2001 at 08:18:00AM -0700, Lance R. Bailey wrote:

"same vendor of course" - that's pretty important for only 4 words.

we've all had to recover things from tapes that are years old. recently i had to recover something from a 1/2" 9 track tape that was a decade old.

10 years ago i had no netapps. in 10 years i might not have any netapps. requiring a specific [10 year old] disk platform to make my recover possible is silly.

what i write to a backup media should require nothing more than a device that can write that media. the original location of that data should not play *any* role in restoring from tape to disk. i have a hard enough time ensuring access to 8mm/4mm/DLT/9track/whizzbang without worrying about having available a ultrix/sunos/hp/solaris/dg-ux/4.1/vnix/qnix/vms/tops-10/whatever system.

vendors that open a connexion between a media device and an ndmp dump process, only to claim later that "hey, we don't know what the ndmp format was, so how can we restore it without having that vendor's product available?" are severely missing both the boat and my personal recomendation.

-- email: lance_bailey@pmc-sierra.com box: Lance R. Bailey, unix Administrator vox: +1 604 415 6646 PMC-Sierra, Inc fax: +1 604 415 6151 105-8555 Baxter Place http://www.lydia.org/~zaphod Burnaby BC, V5A 4V7 I eat tofu -- and I vote. -- White Wave bumper sticker

...

FYI

VERITAS NetBackup NDMP fully supports (release 3.4 onward) restoring NDMP backups to a different NDMP host (same vendor of course). The general NetBackup term for this is "alternate client restore".

...

From: "Traitel, Eyal" eyal@netapp.com To: "Schepers, Jan" Jan.Schepers@nl.origin-it.com, toasters@mathworks.com Subject: RE: Can you not recover a NetApp NDMP backup to another NetApp? Date: Fri, 20 Apr 2001 03:44:29 -0700

Jan,

I am sure this trick is not supported officially by Legato/Veritas/others, but this has been used successfully, and is VERY easy to do:

Just edit /etc/hosts file on your Legato host to point the need-to-be-recovered

filer to the IP of the one that's replacement.

...

As NDMP doesn't really care about that, as long as the restore path is fine...

Eyal.

---

eTraitel - I'm the new eBuzzword around !!!

Eyal Traitel - Filer Escalation Engineer CNA, MCSE, CSA, LCA, NetApp CA

          Network Appliance BV
          Holland Office Center
          Kruisweg 799b
          2132 NG, Hoofddorp
          The Netherlands

Office: +31 23 567 9685 Cellular: +31 6 5497 2568 Email: eyal@netapp.com

---

Get answers NOW! - NetApp On the Web - http://now.netapp.com

-----Original Message----- From: Schepers, Jan [mailto:Jan.Schepers@nl.origin-it.com] Sent: Friday, April 20, 2001 11:45 AM To: toasters@mathworks.com Subject: Can you not recover a NetApp NDMP backup to another NetApp?

Hello list,

possibly you read the following line in the Legato's Networker 6 SysAdminGuide

The Networker Administrator Guide (6.0) shows in chapter 12 , the section on NDMP limitations the following :

NetApp Computers and NDMP Keep in mind the following limitations when you use NDMP and NetApp: * You cannot recover a NetApp NDMP backup to another NetApp. You can only recover data to the original host.

Does this mean that my faith fully daily made backups are worthless in case of a disaster?

rgds,

Yann

---

Steve Kappel steve.kappel@veritas.com VERITAS Software steve@stevekappel.com (Personal)

I don't agree full with your argument. First of all, when changing backup/restore platforms, be that the machine being backed up, the tool backing it up, or the medium backed up to, you must put in place a procedure for legacy restores. If part a requirement of your legacy restore plan is that you need to keep one of that OS, tool, or tape drive around, then you have to keep it around. That's why we have a BudTool server, a machine running Novell NetWare, and a whole host of old, weathered tape drives. =)

i agree completely that legacy restores need to be addressed, and i too have my collection of old tape drives. i fully anticipate having to maintain

1) software that reads the media 2) hardware into which the media fits

after that i shouldn't have to care about the h/w involved in the original data. i even extend that to OS, but conceed that that extension is arguable.

On the other hand, I agree with you that it would be nice if all new technologies were fully backwards compatible. It would also be nice if all

no. i never said that i wanted new technologies to be fully backwards compatible. i don't expect ndmp to read tar, or cpio or even dump. but i don't expect a software vendor to force me to maintain storage h/w long after it or even the company is no longer available.

i have VMS tapes. i don't have a VMS system. but before i lost access to the VMS system i ensured that i had a piece of s/w that would allow me to read the tapes.

i have NeXT tapes. i can read these tapes - 7 years old off a [mostly] dead vendor - on my solaris box. i don't care that the disk format was afs, 4.3, ufs or whatever. i have Tops-10 tapes. if i want to read them, then it is my responsibility to get s/w that will read tops-10 tapes. you get the idea.

tape backup s/w should be disk media independant.

let's say it's 10 years from now. my disk vendor "JaBOD" has gone away a while ago and i've moved to netapps. i have a fire at my site. all my machines are gone. i pull out the DRP and get the backup tapes from offsite. but wait - that "JaBOD" filer i was keeping around for recovery is a pile of molten bits. oops.

should i be required to keep a "JaBOD" filer with my offsite tape storage? if so, that also means i have to move it onsite periodically to test it out - monthly? annually? physically moving equipment regularily is a nice recipe for breaking them. we need to minimize the h/w reliances not expand them.

Veritas cannot guarantee this in any way. NetBackup only knows that it wrote a big long stream of blocks to tape, and it receives a chunk of file history aimed at helping us humans figure out what files are in there. NetBackup doesn't know if that long stream of blocks was NetApp dump format, tar format, cpio, or otherwise. In NDMP, it is the responsibility

having the backup s/w open a stream to the tape and then having the filer dump to is is an inspired idea. really. i think it's fast, slick and a "good thing (tm)".

it's the restore that worries me. the format of the data on tape is not a secret. the filer company that wrote their NDMP dump/restore certainly knows it.

filer companies and backup vendors are very happily and loudly proclaiming their relationships and working partnerships. IMNSHO part of that partnership should either be the format of the data stream or routines to manipulate it. either way would provide a h/w independant restore to happen. is this good for the filer company - on the surface no because it allows my backups to be moved to another filer company's product.

if i liked closed systems, i wouldn't have spent the last 20 years with adventures in unix-land.

i brought this h/w reliance up with a backup vendor. their response was (and i paraphrase): "our backup s/w is intended to handle short term recovery - our s/w is not intended for long term recovery. you should use archival s/w for long term storage."

pretty scary stuff.

-- email: lance_bailey@pmc-sierra.com box: Lance R. Bailey, unix Administrator vox: +1 604 415 6646 PMC-Sierra, Inc fax: +1 604 415 6151 105-8555 Baxter Place http://www.lydia.org/~zaphod Burnaby BC, V5A 4V7 Canada: Not quite as boring as you think. -- Crazy People