Netbackup (usr/openv/netbacku/) subdirectories went missing

Dear All -

Please share your inputs on the workaround or the findings if you have experienced any such issues as mentioned below-

Netbackup directories went missing at overnight leading for backup failure, there were no identity while we referred to audit and var/log/messages logs. Symantec and Redhat are still Investigating on this cause. 

Infra Detail:

OS:  Redhat Linux 6.0
Netbackup Version: 7.5
MP: 0.4
Path: /usr/openv/netbackup/*** All the subfolders in here were found missing ***

Any inputs to investigate more will be helpful to avoid any such instance in future.

Thank you in Advance.