"svc_cifsssuport -setspn" will be available on the upcoming 4.2 version, but contact the Dell EMC Support for immediate support.
I need to use a DNS name that is different from the NAS Server name to connect and use kerberos. Anyone else doing this? We have done it on vnx for 4 years with no issues, worked great.    We have a major application that uses a DNS FQDN that is different from the name of the vnx CIFS server joined to the domain.   We have pre-copied 4 TB and 26 shares to Unity and when we cutover we will need to use the existing DNS FQDN.  I tried as a test to create an A record DNS name with the same IP as a test NAS Server on the Unity. It will connect using the DNS name, the IP, or the actual NAS server name, but for the IP or DNS it defaults to NTLM security protocol not kerberos. If I add the SPNs to the AD computer account, and try to connect using that name, I am prompted for a username and password and get access denied.   On Isilon, we just go to the computer object, attribute editor tab, and add the SPNs in there and right away it works using kerberos.  On VNX, we run the server_cifs test_vdm -setspn -add command and it works.   Here is what I see for this UNITY test computer account and spn: setspn -q host/unityspntest.nas.co.edu Checking domain DC=win,DC=ad,DC=co,DC=edu CN=unitytest,OU=ProductionNAS,OU=File Services,OU=Systems,OU=CLOUD,DC=win,DC=ad,DC=co,DC=edu         cifs/unityspntest.nas.co.edu         host/unityspntest.nas.co.edu         RestrictedKrbHost/unitytest.win.ad.co.edu         RestrictedKrbHost/UNITYTEST         host/unitytest.win.ad.co.edu         host/UNITYTEST  Here is what I see for the prod NAS name for the VNX. It’s a DNS name appnasprd.es.co.edu setspn -q host/appnasprd.es.co.edu Checking domain DC=win,DC=ad,DC=co,DC=edu CN=nasep1,OU=Production,OU=File Services,OU=Systems,OU=CLOUD,DC=win,DC=ad,DC=co,DC=edu         host/appnasprd.es.co.edu         cifs/appnasprd.es.co.edu         host/nasep1.win.ad.co.edu         host/nasep1   The obvious difference is the “RestrictedKrbHost” entries on the computer object from the Unity NAS but I don’t know if that matters I tried removing them and it made no difference.  When I am prompted for credentials trying to connect to the DNS name on the Unity NAS Server, I get the following entries in the security event log for the NAS Server: Event ID 537 Failure Logon/Logoff User: NT Authority\System Computer: UNITYTEST Logon Failure, Reason, An unexpected error occurred during logonUsername  Null Session Logon Type 3 Logon Process: CIFS  error: DC AUTH ERROR  and  Event ID 681 Failure Account Logon User: NT Authority\System Computer: UNITYTEST The Logon to account: Null Session by: EMC CIFS with KERBEROS Failed: The Error code was CIFS  error: DC AUTH ERROR  I opened and SR and they said there are no server_cifs spn commands in unity, you have to do it in AD and contact Microsoft. This morning I contacted one of our local EMC guys and he put me in touch with a guy who had a VSA Unity in a lab and he did the same setup as we did and got the same access denied prompting for credentials.   We were supposed to be doing this migration at 3AM tomorrow morning, but with this issue we postponing. It's frustrating because this was relatively easy on the other platforms. 
How do I add SPNs to use kerberos for a DNS name for a Unity Nas Server?