VNX: Access to CIFS/SMB Shares Lost After Upgrading to File OE 7.1.82.0

File OE Upgrade to 7.1.82.0

After upgrade to File OE 7.1.82.0, access to CIFS/SMB shares is lost a short time after DM is rebooted with the new DART version.

CIFS server domain is a single label domain, that is the domain does not have a prefix/suffix and no dot in domain name.

server_log shows these log errors:

2018-06-28 13:58:52: SMB: 4: Unsupported authentication mode: authMethod:4, kerberosSupport:1, negoMethod:0
2018-06-28 13:58:52: SMB: 3: OpenAndBind[NETLOGON] DC=DC2 failed: Bind_OpenXFailed DOMAIN_CONTROLLER_NOT_FOUND
2018-06-28 13:58:52: SMB: 3: Can't open NETLOGON file for DC=DC1
2018-06-28 13:58:52: SMB: 6: DC0x01bce32808: setDCDown DC, refresh if needed (origin=netLogonAuth2)
2018-06-28 13:58:52: SMB: 6:  DC*DC1(192.168.xx.xx) R=331 T=0 ms S=17,0xc0000233/27
2018-06-28 13:58:52: SMB: 3: W2KDCRequestB:setDCDown(DC1)
2018-06-28 13:58:52: SMB: 4: Cannot get kerberos TGT for 'user1.mydomain' with user 'mydomain\cifsserver$': No '.' found in the user domain name
2018-06-28 13:58:52: SMB: 4: Cannot get kerberos TGT for 'user2.mydomain' with user 'mydomain\cifsserver$': No '.' found in the user domain name
2018-06-28 13:58:52: SMB: 4: Cannot get kerberos TGT for 'user3.mydomain' with user 'mydomain\cifsserver$': No '.' found in the user domain name

Access is working for a short time after DM reboot, although slow and sluggish.

Additional Symptoms:

pdc dump returned i/o error

----------------- pdc dump ------------------------------
xxxxx : commands processed: 0

Error 4020: xxxxx: Input/output error
Timed out

cifsThrd command showed a lot of blocked cifs threads:

----------------- cifsThrd ------------------------------
tjure-dm1 : commands processed: 1
command(s) succeeded
output is complete

1530176768: SMB: 6: cifsThrd: checking blocked threads
minimum: 0/384 threads, 5 seconds
1530176768: SMB: 3: List of blocked threads
1530176768: SMB: 3: 2SMB003 BLOCKED for 58 seconds in SessionSetup
2SMB003 at 0x000e5ecd60: WaitingMutex at 0x005eb83d80 (malloc heap)

ctx=[0x0007a6e808-0x0007a6eb10] Client=xxx
DC=[0x0007dfb008-0x0007dfb260] SVEN
1530176768: SMB: 3: 2SMB004 BLOCKED for 42 seconds in SessionSetup
2SMB004 at 0x000e5ed0b0: WaitingMutex at 0x005eb83d80 (malloc heap)

ctx=[0x005ea58008-0x005ea58310] Client=xxxx
C=[0x0007dfb008-0x0007dfb260] SVEN
1530176768: SMB: 3: 2SMB005 BLOCKED for 34 seconds in SessionSetup
2SMB005 at 0x000e5ed400: WaitingMutex at 0x005eb96180 (malloc heap)

-----------------------------------------------------------------------

Customer is using a single label domain "dc-domain":

CIFS Server XXXX[DC-DOMAIN] RC=1442
Full computer name=XXXX-domain realm=DC-DOMAIN
Comment='EMC-SNAS:T7.1.83.2'
if=tjure01 l=192.168.xx.xxx b=192.168.xx.xxx mac=0:xx:xx:xxx:xx:xx
FQDN=XXXX.dc-domain (Updated to DNS)
Password change interval: 0 minutes
Last password change: Thu Jun 28 07:23:39 2018 GMT
Password versions: 2

The 7.1.82.0 release enables the use of Server Message Block version 2 (SMB2) as the dialect for secure channel communications between the VNX CIFS server and the Active Directory domain controller.
There is a code issue with SMBv2 DC communication and single label domains.

If your CIFS server is joined to a single label domain and you experience this issue after upgrade to File OE 7.1.82.0, there is a workaround or a hotfix available. The hotfix is based on File OE Release 7.1.83.2.

Contact Dell Technical Support or your Authorized Service Representative, and quote this knowledge base article ID.