ERROR: Cannot resolve `localhost'

This article is for Amanda Enterprise (AE) 

Issue Symptoms

ERROR: Cannot resolve `localhost'.
NOTE: skipping tape-writable test
Tape HardDisk-4 label ok
Server check took 1.878 seconds
Amanda Backup Client Hosts Check
WARNING: Usage of fully qualified hostname recommended for Client localhost.
WARNING: localhost: selfcheck request failed: getaddrinfo(localhost): Name or service not known

Issue Description

The backup server is unable to resolve hostname "localhost."

Resolution

Add the following lines to the /etc/hosts file on the backup server:

127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6