3-way restore to address migration from one nas to another?

[jim_dalton]

We are changing filer providers but we need a way to be able to access backups made on our "old" filer.

The original backups were to tape

Is it possible to run the old filer simulator (VM) and do 3-way ndmp to it via the new filer? Ie tapes attached to new filer, reads the data and sends it to the VM

Thanks in advance Jim 

[Nicolai]

The only option I knwo of is keeping a device around that is able to read the "old" NDMP format.

I do not know any emulators.

[Marianne]

Another option would be to take a file-level backup via NFS/CIFS on a media server.

[areznik]

NetApp has an emulator for sure and i believe EMC does too. I have tried NetApp's one for restores and it works. But keep in mind that these are evaluation products and not designed for this use case. If they dont work you wont get any support from the Vendor

[RonCaplinger]

Jim, you probably already know this, but for those who might read this in the future, that's always been the downside of NDMP backup.  The NDMP protocol is a transport protocol to move data from device to device, with no storage format involved.  The tapes are written in different formats by each filer vendor; even though NetBackup may be involved in the backup, it does not decide the tape format.  Tapes written by a NetApp can't be read by EMC, or Isilon, or Quantum, etc.  If your data retention period is short enough, this isn't usually an issue.  But when you have to retain data for years, NDMP backups present a unique problem in recovering that data.

I don't believe there is any easy way to access the data on the old tapes.  Based on how often you think you will need to access the old data, I would recommend:

1. Probably never, only in legal cases -  just make it part of your plan to send the tapes off to a data recovery vendor (Kroll Ontrack?) in those few instances that might happen.
2. A little more frequently, maybe a few times a year - keep the old filer hardware onsite and available to power up if necessary to access the tapes.
3. Frequently enough - create a disk storage unit and allow Netbackup to duplicate the backups from the old tapes to disk, then duplicate them from disk to new tapes on the new filer. (I've never done this, but assume it would work; someone please corect me if wrong.)

[jim_dalton]

Lots of useful input...thanks so far.

-Yes netapp has an emulator, thats the one we would be using.

-doing occasional restores would be the anticipated norm, though some could be 100s Gb in size.

-Cant simply keep the old storage kit available in case its needed...it costs money, lots of. 

-interesting idea to create disk storage and duplicate the tape images onto disk. This could be doable.

I guess my question might be boiled down to which: server(s) actually do the command and interpretation and which are components that just act as intermediaries? areznik: your nput suggests that only the simulator is doing the smart work and your comments give me some confidence.

Jim

[jim_dalton]

Just thinking about the duplicate images to disk option...I wonder if theres a gotcha there? In order to duplicate from tape to disk, dont I have the same problem...the system that created the backup must be used to read and duplicate it? Can netbackup duplicate ndmp backups from tape to disk,,,,are they even written in a duplicate-able and portable format when NDMP is involved? Your input appreciated.

[Nicolai · Accepted solution]

If the NDMP device wrote the image directly, it will be in the vendor propriety format (not Netbackup). And even if you get away by duplicating the image to disk I don't think Netbackup will be able to read it (should be simple to test).

Have you asked Netapp what to do with the old backup ?

They may have suggestion.