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7 Posts
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1997
July 15th, 2011 09:00
NDMP backup TYPE variable ignored?
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: 0
1310745654: NDMP: 4: Session 021 (thread ndmp021) Name: FILESYSTEM Value: /jh-cifs
1310745654: NDMP: 4: Session 021 (thread ndmp021) Name: HIST Value: y
1310745654: NDMP: 4: Session 021 (thread ndmp021) Name: TYPE Value: dump
1310745654: 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
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8.6K Posts
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July 18th, 2011 15:00
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
337 Posts
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July 18th, 2011 00:00
This thread is moved from ECN > Support Forums > General Topics > Discussions
to ECN > Support Forums > Celerra
Peter_EMC
674 Posts
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July 18th, 2011 02:00
NDMP does only support three backup types:
even if it is using server_archive.
Please check the NDMP manual for additional informations.
JoeHartley3
7 Posts
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July 18th, 2011 12:00
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
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8.6K Posts
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July 19th, 2011 07:00
Just curious - why do you care about the data format?
JoeHartley3
7 Posts
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July 19th, 2011 07:00
Thanks for this answer, it makes it clear what I can expect for the data that gets written to tape. Thanks again!
Rainer_EMC
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July 25th, 2011 08:00
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
7 Posts
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July 25th, 2011 08:00
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.