Optimized Synthetic Backups failing with error 79 for automounted file systems

[LuisLiendo]

Optimized Synthetic Full backups failing with error 79 for all automounted file systems

Whiles using multistreams and ALL_LOCAL_DRIVES.

Regular Full backups and Incremental backups completed successfully.

When trying to generate a Synthetic Full backup , all the streams generated for automounted file systems will fail with error 79.

Example:

# cd /apps/scripts
/apps/scripts
# ls -ls
total 8
   4 -rw-r--r--    1 root     system         1676 Nov 07 2005  csxx.dsm
   4 -rw-r--r--    1 root     system         1649 Nov 07 2005  ksxx.dsm
   0 drwxr-xr-x    2 root     staff           256 Jan 05 2007  standard2
# df -k .
Filesystem    1024-blocks      Free %Used    Iused %Iused Mounted on
/export/apps/scripts     1441792    331472   78%    36201    32% /apps/scripts

Note that the filesystem /export/apps/scripts (to the left) has been auto mounted or manually mounted as /apps/scripts

The original file system /export/apps/scripts is backing up and synthesizing successfully.

/export/apps/scripts => /apps/scripts are the same

Netbackup is seeing /apps/scripts as an unsupported image format for Optimized Synthetic Full backups , resulting in only this stream failing with error code 79. 

Any suggestions how to get rid of that error ?

How to indicate Synthetic full backup to ignore automomounted filesystem as a regular full or incremental backup will do ?

[Nicolai · Accepted solution]

Netbackup does not follow file system it think is are "remote" e.g. NFS

You need to check mark the "follow NFS" option in the policy to let Netbackup follow automounted directories.

See this tech note: 

http://www.symantec.com/docs/HOWTO33438

[LuisLiendo]

I think this problem is not related with NFS.

So far the only way we have found to get rid of this error is to regenerate a regular full backup. After that the synthetic backups will work for a while. Was advised to schedule a regular full backup at least every other month to keep these errors away.

The problem is that we were using Synthetic backups to avoid doing the regular ones as for they take days to complete.

[Yasuhisa_Ishika]

Which version of NetBackup are you using?

Have you already tried to exclude this loopback mount by exclude_list?