We suggest you to add the host/computer name and IP address of Linux machine correctly in hosts file of the Media server (C:\Windows\system32\drivers\etc\) Add the host name \computer name and IP address of the Media server in hosts file of the Linux machine.
Open RALUS.CFG file and enter the IP address of the Media server.
Restart Backup Exec services and check the results.
We hope this helps. The error generally occurs due to incorrect name resolution