TSM NDMP no Differential, only FULL

[edaguero]

Hi,
We have an EMC Isilon configured with a Backup Accelerator and cannot perform differential backups using TSM 5.5.

There are several virtual filespaces defined on TSM, and run backups on a weekly basis.
Numerous FULL backups have been executed across all filespaces, even test filespaces with less that 10MB of data, all complete Successfully according to the TSM actlog.
However the backups always default to FULL even though mode=diff is defined.

The command we use is -
backup node isilon /backupfolder toc=yes wait=yes mode=differential

This occurs on every filespace. I can scroll through the TOC for each filespace, and can restore the entire filespace to an alternate location without problem, so the backups are definitely working, however no differentials work.

Any ideas?
Thanks

 

[edaguero]

anyone have any ideas as to why this could be happening?
Screendump of act log


tsm: TSM01>backup node isilon /BackupTest mode=diff toc=yes wait=yes
ANR0984I Process 215 for BACKUP NAS (FULL) started in the FOREGROUND at 10:52:23 AM.
ANR1063I Full backup of NAS node ISILON, file system /BackupTest, started as process 215 by administrator TEST.
ANR1067I NAS Backup process 215 completed.
ANR0986I Process 215 for BACKUP NAS (FULL) running in the FOREGROUND processed 1 items for a total of
11,993,088 bytes with a completion state of SUCCESS at 10:53:45 AM.


This has now been run around 5 times, same results. TOC is fine, and I can also perform a full restore on all data.

 

[Peejay]

Hi, do not know if your problem is solved, but anyway, I can suggest a possible solution.
We have been struggling too with this strange behaviour, though everything setup to perform full/diff only fulls occurred. After some serious headbreaking this it what I came up with and (for us) it worked:
We backup a netapp vseries with various vfilers defined. Each vfiler we backup based on a collection of virtualfs definitions. I assume you do the same with your isolon. The problems exists in the virtualfs definition : as soon as the virtualfsname is the same as the real path name that you want to backup the full/diff fails. so giving the virtualfs a slightly different name as the original path you want to backup does the trick. example : On the nas environment I want to backup the folder /customer . I defined a virtualfs /customer_home (pointing to that backupfolder). backup /customer_home blabla command works fine now.
Don't ask me where this behaviour originates from, I cannot tell you, our full/diff backups work fine though. Wild guess it has something to do with the TOC and comparing that against what to backup.

Bye, Peejay

 

[edaguero]

Thanks for your response.
We ended up finding that it was indeed related to the TOC. The issue was originated on the EMC NAS side not giving TSM the appropriate TOC info.
After much liaising with EMC, they admitted that there was a fault with the ISILON OS version we were running, and subsequently upgraded our software.
Problem went away thereafter.