Time to Time DB2 Backup Faliure

Hi,

We have Networker 9.1 that deployed on a Win 2012 R2. We are schedule a DB2 full backup on every day 3 am. Past few months we are facing the backup failure in time to time. In the every time when the backup failed we got the below error.

“Backing up the 'PB_PROD' database.

Unable to backup PB_PROD database due to backup request failure, SQLCODE : -2025, SQL2025N An I/O error occurred. Error code: "3". Media on which this error

occurred: "VENDOR".

NMDA backup failed.

64673:nsrdasv: Unable to backup PB_PROD database due to backup request failure, SQLCODE : -2025, SQL2025N An I/O error occurred. Error code: "3". Media on which this error

occurred: "VENDOR".

--- Job Indications ---

prdbsvr1:DB2:/PB_PROD/NODE0000: retried 1 times.”

But after we restart the NW services from next day onwards backup was run as normal. DB backup size is ~1.5 TB. We have open several SR‘s with DELL EMC NW support team. As per them in the very first time they advised to restart the NW services. As I previously said after restarting the services it was runnin fine. In the second time when we open the SR they asked to created a separate ddboost device to backup the data. That thing also we already did. Now we yesterday backup was again failed with the same error.

Is anyone can advised how to solve this issue permanently.