Dell Unity: CAVA server went offline and recovered intermittently

Summary: CAVA server went offline and recovered intermittently: "The virus checker server xx.xx.xx.xx has encountered an error and is no longer operational.(Error: ERROR_AUTH 64)" :: Category=User Component=DART_VC "Virus checker server xx.xx.xx.xx is online." :: Category=User Component=DART_VC. ...

This article applies to This article does not apply to This article is not tied to any specific product. Not all product versions are identified in this article.
Check out other resources

Symptoms

The issue happened on Unity code 4.4.0.1536311042 and Windows Server 2016.

Issue Description:

  1. Customer configured CAVA, they got below error intermittently that CAVA server went offline and came back online in a few seconds.
    You see following error logs in EMCSystemLogFile.log

    "2018-12-28T02:18:22.331Z" "n1988006_spa" "Kittyhawk_safe" "26056" "unix/spa/root" "ERROR" "13:10510021" :: "The virus checker server xx.xx.xx.xx has encountered an error and is no longer operational.(Error: ERROR_AUTH 64)" :: Category=User Component=DART_VC
"2018-12-28T02:18:41.486Z" "n1988006_spa" "Kittyhawk_safe" "26056" "unix/spa/root" "NOTICE" "13:1051001d" :: "Virus checker server xx.xx.xx.xx is online." :: Category=User Component=DART_VC
"2018-12-28T02:35:42.361Z" "n1988006_spa" "Kittyhawk_safe" "26056" "unix/spa/root" "ERROR" "13:10510021" :: "The virus checker server xx.xx.xx.xx has encountered an error and is no longer operational.(Error: ERROR_AUTH 64)" :: Category=User Component=DART_VC
"2018-12-28T02:35:51.678Z" "n1988006_spa" "Kittyhawk_safe" "26056" "unix/spa/root" "NOTICE" "13:1051001d" :: "Virus checker server xx.xx.xx.xx is online." :: Category=User

    The same error messages were also reported in c4_safe_ktrace.log like:

    2018/12/28-21:32:25.865594 115K     7F86FEB3E709     sade:VC: 3:33:[Rick]  The virus checker server 160.46.85.196 has encountered an error and is no longer operational.(Error: ERROR_AUT
2018/12/28-21:32:25.865596    0     7F86FEB3E709     sade:VC: 3:33:[Rick]  H 64)
2018/12/28-21:32:25.865617   19     7F8790D83702     sade:SOCK_STREAM: 3:[core]  T_DISCON_REQ: (fd=0x1a0, NS=0) ShutdownStream() request UNSUPPORTED!
2018/12/28-21:32:25.865622    4     7F8790D83702     sade:SOCK_STREAM: 3:[core]  T_DISCON_REQ: (fd=0x1a0, NS=0)  Handling as DisconnectCloseStream()!
--
2018/12/28-21:32:53.272520    0     7FC1D8ADC70A      std:PSMSYS:PSMSYS:psmDataAreaClose(1:13): PENDED...
2018/12/28-21:32:55.127022 1.8M     7F86FEB3E702     sade:VC: 5:29:[Rick]  Virus checker server 160.46.85.196 is online.
2018/12/28-21:32:55.128201 1177     7F8790DC7704     sade:SOCK_STREAM: 3:[core]  T_DISCON_REQ: (fd=0x1cb, NS=0) ShutdownStream() request UNSUPPORTED!
2018/12/28-21:32:55.128206    3     7F8790DC7704     sade:SOCK_STREAM: 3:[core]  T_DISCON_REQ: (fd=0x1cb, NS=0)  Handling as DisconnectCloseStream()!

  2. The error happened randomly with no certain pattern. It appears CAVA service is not impacted.

  3. KB#462457 was followed up, but we did not see a time skew between CAVA server/Unity/Windows DC server.

  4. Network traces show that the CAVA server sent FSCTL_VALIDATE_NEGOTIATE_INFO Ioctl request but Unity did not respond and disconnected the TCP connection.
    When the issue happened, the CAVA server sent a FSCTL_VALIDATE_NEGOTIATE_INFO Ioctl request, but Unity did not respond and Finished the connection.

    # Good case example

    5817    0.433916    CAVA_IP    CIFS_IP    SMB2    156    Tree Connect Request Tree: \\rick\CHECK$
5820    0.433983    CIFS_IP     CAVA_IP    SMB2    138    Tree Connect Response
5823    0.434164    CAVA_IP    CIFS_IP    SMB2    212    Ioctl Request FSCTL_VALIDATE_NEGOTIATE_INFO
5826    0.434217    CIFS_IP     CAVA_IP    SMB2    194    Ioctl Response FSCTL_VALIDATE_NEGOTIATE_INFO  <=========== good case

    # Bad case example

    1806    0.096779    CAVA_IP    CIFS_IP    SMB2    156    Tree Connect Request Tree: \\rick\CHECK$
1807    0.096854    CIFS_IP     CAVA_IP    SMB2    138    Tree Connect Response
1818    0.097124    CAVA_IP    CIFS_IP    SMB2    212    Ioctl Request FSCTL_VALIDATE_NEGOTIATE_INFO
1820    0.097200    CIFS_IP     CAVA_IP    TCP    54    445   52006 [FIN, ACK] Seq=85 Ack=261 Win=304 Len=0   <=========== bad case

  5. This issue would impact CIFS data copy like using emcopy to try to and migrate data from VNX to Unity.
    They run multiple copies simultaneously, and intermittently different ones fail each time with the error.

    Client OS : Microsoft (build 9200)
TH000 : 02:28:08 : ERROR (53) : unable get server info from \\cifsserver.exmaple.net

 

Cause

This is a problem, since Unity must validate the information with the initial connection not with the binded connection. And it does cause customer issue.

 

Resolution

This is the problem only with the SMB version 3.0.2 even if they switch to 3.1 or 2.1 it works. And even in 3.0.2 they have a workaround.

Workaround: Dislabe Multichannel on Windows server or CAVA server

Run PowerShell as administrator, then:

PS C:\windows\system32> Get-SmbClientConfiguration


ConnectionCountPerRssNetworkInterface : 4
DirectoryCacheEntriesMax              : 16
DirectoryCacheEntrySizeMax            : 65536
DirectoryCacheLifetime                : 10
DormantFileLimit                      : 1023
EnableBandwidthThrottling             : True
EnableByteRangeLockingOnReadOnlyFiles : True
EnableInsecureGuestLogons             : False
EnableLargeMtu                        : True
EnableLoadBalanceScaleOut             : True
EnableMultiChannel                    : True
EnableSecuritySignature               : True
ExtendedSessionTimeout                : 1000
FileInfoCacheEntriesMax               : 64
FileInfoCacheLifetime                 : 10
FileNotFoundCacheEntriesMax           : 128
FileNotFoundCacheLifetime             : 5
KeepConn                              : 600
MaxCmds                               : 50
MaximumConnectionCountPerServer       : 32
OplocksDisabled                       : False
RequireSecuritySignature              : False
SessionTimeout                        : 60
UseOpportunisticLocking               : True
WindowSizeThreshold                   : 8

PS C:\windows\system32> Set-SmbClientConfiguration -EnableMultiChannel $false

Confirm
Are you sure you want to perform this action?
Performing operation 'Modify' on Target 'SMB Client Configuration'.
[Y] Yes  [A] Yes to All  [N] No  [L] No to All  [S] Suspend  [?] Help (default is "Y"): yes
PS C:\windows\system32> Get-SmbClientConfiguration


ConnectionCountPerRssNetworkInterface : 4
DirectoryCacheEntriesMax              : 16
DirectoryCacheEntrySizeMax            : 65536
DirectoryCacheLifetime                : 10
DormantFileLimit                      : 1023
EnableBandwidthThrottling             : True
EnableByteRangeLockingOnReadOnlyFiles : True
EnableInsecureGuestLogons             : False
EnableLargeMtu                        : True
EnableLoadBalanceScaleOut             : True
EnableMultiChannel                    : False
EnableSecuritySignature               : True
ExtendedSessionTimeout                : 1000
FileInfoCacheEntriesMax               : 64
FileInfoCacheLifetime                 : 10
FileNotFoundCacheEntriesMax           : 128
FileNotFoundCacheLifetime             : 5
KeepConn                              : 600
MaxCmds                               : 50
MaximumConnectionCountPerServer       : 32
OplocksDisabled                       : False
RequireSecuritySignature              : False
SessionTimeout                        : 60
UseOpportunisticLocking               : True
WindowSizeThreshold                   : 8

 

Affected Products

Dell EMC Unity Family

Products

Dell EMC Unity Family |Dell EMC Unity All Flash, Dell EMC Unity Family, Dell EMC Unity Hybrid
Article Properties
Article Number: 000050509
Article Type: Solution
Last Modified: 07 Oct 2025
Version:  4
Find answers to your questions from other Dell users
Support Services
Check if your device is covered by Support Services.