NDMP backup TYPE variable ignored?

Question

I have been working on getting backups of a Celerra written to a virtual tape library on a UNIX machine using NDMP.  According to all the documentation I've read, I should be able to pass an environment variable TYPE to specify the format of the dump.  Further, the Celerra should accept the values of 'dump' and 'tar'.  I know the variable is getting passed, but it seems to always be ignored: 1310745654: NDMP: 4: Session 021 (thread ndmp021) < Backup type: dump >1310745654: NDMP: 4: Session 021 (thread ndmp021) Name: BASE_DATE Value: 01310745654: NDMP: 4: Session 021 (thread ndmp021) Name: FILESYSTEM Value: /jh-cifs1310745654: NDMP: 4: Session 021 (thread ndmp021) Name: HIST Value: y1310745654: NDMP: 4: Session 021 (thread ndmp021) Name: TYPE Value: dump1310745654: NDMP: 4: Session 021 (thread ndmp021) tape service is on a remote side, CALLER_ADDRESS 0x11b94f1. Note the backup type is dump. As the backup finishes, this line is shown by server_log: 1310745654: NDMP: 6: Thread nasa00 server_archive: emctar vol 1, 5 files, 0 bytes read, 272731 bytes written It looks like server_archive is always invoked to use the emctar format, whether I pass dump or tar.  Further, the doc for server_archive says that other formats, including ustar (which is compatible with POSIX-standard tar implementations), are supported.  To me, server_archive looks a *lot* like the pax command, so I'm hoping that I can get an NDMP backup sent from the Celerra in a format other than EMC's own emctar. Does anyone know if that's possible? Thanks! Joe H.

Rainer_EMC · Accepted Answer

With Celerra NDMP the data format for dump and tar is the same - the difference us mainly how the fs is walked (depth-first vs. breadth-first)

VBB is very different - it's a block copy like a dd

Rainer

Phukon · Answer

This thread is moved from ECN > Support Forums > General Topics > Discussions to ECN > Support Forums > Celerra

Peter_EMC · Answer

NDMP does only support three backup types: tar dump vbb even if it is using server_archive. Please check the NDMP manual for additional informations.

JoeHartley3 · Answer

I understand that the values for TYPE is limited but the data written to my virtual tape device is identical whether I use dump or tar for TYPE. That was what prompted my original question: Is the value of this variable ignored? As my magic 8 ball would say, "All signs point to Yes".

I will give "vbb" a try and see if there's any change to the data.

Thanks!

- Joe

Rainer_EMC · Answer

Just curious - why do you care about the data format?

JoeHartley3 · Answer

Thanks for this answer, it makes it clear what I can expect for the data that gets written to tape.  Thanks again!

Rainer_EMC · Answer

And here the age-old answer:

The NDMP data format is vendor specific (not specified in the standard) so in general you need the same hardware/software combo to restore

AFAIK as I know there is one vendor who did write a cross-platform restore – search here on the forum about a discussion on CommVault

(limited of course – you wont get back Windows owner or ACLs)

Rainer

JoeHartley3 · Answer

It's the age-old story - questions are being asked about the ability to recover data from a backup image if the original hardware is unavailable.

Celerra

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