SQL dumps or removal of old dumps do not happen at the same time as NBU backups.

[NIKHIL234656595]

You need to work with SQL dba to ensure that SQL dumps or removal of old dumps do not happen at the same time as NBU backups. 
Here we see a SQL dump file that 'dissapeared' inbetween the start of the backup and the time that NBU tried to create snapshot.
This is not a NBU problem - find out from SQL dba what happened to this SQL dump.

 SQL dumps or removal of old dumps do not happen at the same time as NBU backups. 

What does above statement means?

[mph999]

It means exactly what it says.

Do not allow the SQL dumps to be created or removed during the time NBU is backing up.

You would need to speak with the DBAs to ensure this doesn't happen.

I'm sure Marianne will be along at some point to point out any errors I have made ... I'm NOT a DBA.

M

[NIKHIL234656595]

What are these SQL dumps or old dumps?

[mph999]

As a guess ...

You cannot backup a running database, so these 'dumps' will be like a 'snapshot' of the database, I think ...

Martin

[NIKHIL234656595]

So when backup is running, DBA should not dump the sql fdatabase files?

[Marianne · Accepted solution]

NIKHIL, we've been through this before ... sigh.... 

https://www.veritas.com/connect/forums/symantec-netbackup-use-ldf-mdf-files

https://www.veritas.com/connect/forums/sql-difference-between-bak-and-bkf-files

Your opening post is copy & paste from this post: https://www.veritas.com/connect/forums/snapshot-error-156-2#comment-7669571

My post means EXACTLY what is says - you need to SPEAK to your SQL dba  - the SQL backup to disk (dump) should not take place at the same time as NBU backups.

These SQL dumps take up a lot of space - SQL dba needs to remove/delete old disk backup files (dumps) to make space for new backups/dumps.
You need to tell SQL dba what the NBU backup window is - disk maintenance to delete old disk backups (dumps) should not happen at the same time that NBU backups are running.
We could see in your status 156 post that the SQL dump disappeared (deleted by dba?) while backup was running.