We need more info. Tell us how exactly the backup is done? What is NBU policy type?
We know that the NBU for SAP agent does not support DB2. Does this mean that you are using DB2 agents?
Have you created any log folders on the DB2 client?
Do you have log folders on the master and media server?
What is Client Connect and Client Read timeout on the media server set to?
The default of 300 (5 minutes) is normally not enough for large databases - the recommendation is 1800 (30 minutes).
NetBackup for DB2 Administrator's Guide http://www.symantec.com/docs/DOC5166 says the following about DB2 error 518 on p.137:
Message: NetBackup Write Failed
Cause: NetBackup encountered errors when writing a backup image.
So, we are going to need NBU logs to troubleshoot.
The above guide will tell you in Troubleshooting chapter which log folders are needed on DB2 client.
Please note that some folders need 777 permission.
On NBU master and media server, we need the following logs:
On master: bprd (NBU must be restarted to enable this log)
On media server: bpbrm and bptm
After next failure, check on DB2 client which log folders are written to. Check logs for errors.
Check in master's bprd log if connection request is received from client. See if master is able to resolve client IP to hostname that corresponds with Client name in policy.
Check bpbrm log on media server to trace connection attempt to client and if bptm process is started.
If you want us to assist with log analysis, please rename log to reflect process name (e.g. bprd.txt) and upload as File attachments.
(We do not always have the time to sift through lengthy logs, but will try...)
