Backup CIFS share differential with NDMP on NetApp

[felidae]

Hi all
There are severeal threads dealing with problems of differential backups...maybe already too many...
So here is the environment:
- BackupExec 12.5 rev. 2213
- Storage NetApp FAS2050, Ontap 7.3.1.1P7
- HP MS2024 library, 2 drives (FC)
- NDMP is installed, the sources are defined in the inclusion/exlusion list (no .snapshot!), the job is "differential (no resetting archive bit)" and runs from mo-sat.
- There is a Full-Backup job (resetting archive bit) running every Sunday, and doing fine in 16hrs roughly 2.5TB, 7M files
- The next Differential backup on Monday also backs up the same amount of data and files, thus doing again a "Full", which is not the idea...

 What I already understood from other threads:
When doing Full/Differential jobs they must have the same type, either "last time modified" or using archive-bit. Here we are using the archive-bit
The Full job should reset all the archive bits, so the following Differential should be smaller

We examined that by random samples and it looks, like BE is not resetting the archive-bits.
That would explain, why the diff-job on Monday also backs up 2.5TB resp. 7M files.

The question is: did I miss something or is this behaviour a bug, or something NetApp related, or not provided by protocoll or whatever?

Thanks (for answering maybe same questions again and again)
Markus

 

[ffmpeg]

hi
this may help
https://www-secure.symantec.com/connect/forums/backupexec-11d-not-resetting-archive-bit#comment-3079351

[teiva-boy]

 The above link seems pretty spot on in regards to NDMP.  Start with that.

When doing an NDMP based backup, BE does NOT reset the archive bit.  There is something native within the filer that tracks these changes.  

[Colin_Weaver · Accepted solution]

 BE calls the processes that are designed into the filer in order to protect data on a NetApp (when using the Backup NDMP Agent/Option) - the NetAPp Processes don't support incremental backups in the way you are used to on a Windows Server - instead they use Levels - to find out more information on Levels you probably need to be looking at NetApp's own support information.

From a BE point of view - the Incremental / Differential /Full settings in the backup job is ignored because you are not doing a Windows File System backup. Instead the settings in the NDMP section in the Backup job are used - which is where you can define the Levels. 

If attempting to backup over a share (so not using the NDMP Option) you can't use Archive Bit - as the share level access to what is actually a Linux based OS does not allow that. Also you can't used modified time as that uses a mechanism that I believe is based on Windows Journalling.

Be aware that if your filer contains a LUN - this can never be Incrementally or differentially backed up from the filer - as it looks like 1 file - you couldbackup the contents directly from the WIndows Server that the LUN is mounted on - and then archive bits probably would work (but only for the contents of the LUN)