If you choose the Red Hat v6 "minimal install" for your Softlayer RHEL servers, the libraries needed to use the NFS space (samba) are not installed. To install them, log in and type:
sudo yum install samba-client samba-common cifs-utils
Accept the installation, then mount the drive. For example:
mount -t cifs -o username=WWWW,password=XXXX //nas301.service.softlayer.com/YYYY /mnt/shared
Note: The username has been replaced by WWW, the password has been replaced by XXXX, and the account has been replaced by YYYY. The nas301 server might even be replaced by a different one for your account. Get the details for your own NFS shares, or order additional storage, by logging into SoftLayer and going here: https://control.softlayer.com/storage/file or, in the old portal, here: https://manage.softlayer.com/NetworkStorage/summaryForNasType/NAS.