Snapshot fails with error 20
Snapshot creation fails when a mount point used in the backup selection contains a symbolic link. The reason for snapshot failure is that NetBackup does not support a symbolic link as a mount point in the backup selection for a policy.
For example, consider two directory structures /dir1/dir2 and /dir3/dir4 and ln -s /dir1/dir2 /dir3/dir4 is the symbolic link.
If the path /dir1/dir2/dir4 is used as mount point in backup selection, policy validation skips such mount point and succeeds. Further if user runs manual backup for a policy, Snapshot fails with error 20.