Dell EMC Unity – Fix for “Domain Controller servers configured for the SMB server are not reachable”. Check Network Connectivity

My workplace has a number of All Flash Unity Arrays in Production, typically used as the “swiss army knife” for storage needs.

They have proven to be very solid, well performing units as both block and nas hosts, but there has been a peculiar occurrence of alerts displayed periodically, regarding NAS servers being unable to reach any of the configured LDAP servers.

This seemed quite odd, as each time I checked, they were indeed reachable and seemingly error free. There was also no issue with configured AD logons and access to NFS exports using AD based accounts. No issues or alerts were generated form disparate monitoring systems.

The errors are shown following, and were in two forms, 1 for SMB and one for other NAS services ;

  1.  “None of the LDAP servers configured for LDAP client of the NAS server are reachable. Check network connectivity. Ensure at least one LDAP server is available and the storage system can access it” 

    2.  “Domain Controller servers configured for the SMB server **** are not reachable”

  

This seemed to occur roughly twice a day

When version 4.4 of the Unity OE was released, I updated quite quickly for a number of other reasons. A few days passed and I noticed that these errors had ceased. Uh huh ! A quick check of the release notes showed;

“938138/ 9119965/8 635547 Domain Controller alerts occurred every 10 hours when the Kerberos ticket expired. The NAS server in the domain can’t reach any Domain Controller. The code was updated to handle ticket expiration gracefully to avoid alerts.”

Bingo ! The alert has not been sighted since the upgrade. Happy Days

So, if you’re having issues with Unity and phantom/false LDAP server alerts, upgrade to 4.4.0.x  

Original (Affected) Code version: 4.1.2.9257522

Fixed in Code Version: 4.4.0.1534750794

Release Notes 

 

 

 

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