Hi Raj,
I think it would be wise to define (WHOLE backup) first.
I guess you mean the backup with the new Backup and Recovery tool, coming in SAS 9.4, but I am not sure.
By the way, did you check that your "complete" backup (Backup and Recovery, or your customized backup) and the standalone metadata backup (SMC) are scheduled for the same time, the weekly one?
By default, the standalone metadata backup is scheduled for every day at 1:00. The complete backup (with the Backup and Recovery Utility) is scheduled by default for Sundays at 1:00. Any chance that both are running at the same time, therefore, files + metadata are locked for one of them?
PS. I am pretty sure the logs can say something good, maybe you need to look for additional log files.
Regards,
Juan