Dell EMC Unity: Windows 10 and Windows 2019 Server users unable to access SMB shares (User Correctable)
Summary: User upgraded to Windows 10 or Windows 2019 Server version 1903. Windows 10 and Windows 2019 Server users unable to access SMB shares.
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This article does not apply to
This article is not tied to any specific product.
Not all product versions are identified in this article.
Symptoms
The user may see errors similar to these while accessing the SMB share :
Windows cannot access \\servername". Check the spelling.... Error code 0x80004005 Unspecified error.
Windows cannot access \\servername". Check the spelling.... Error code 0x80070035 The Network path was not found
Example:
For more details, please refer to DTA 534173: Dell EMC Unity: Windows users may be unable to access Common Internet File System (CIFS) shares when Server Message Block (SMB) 3.1.1 is running, which may result in potential data unavailability
Cause
- A change in Windows 10 version 1903 and Windows Server 2019 1903 is causing an SMB communication issue with Unity systems running a max SMB dialect of SMB 3.1.1.
- There may be some pre-release versions earlier than 1903 which are affected (i.e. MSDN or developer versions), but we have not tested any but the GA version of Windows 10.
- Dell EMC Unity OE versions 4.2 and higher are affected.
- VNX and VNXe are not impacted, as SMB 3.1.1 is not yet supported on these platforms.
Resolution
Fix:
This issue is fixed in Unity OE 5.0.1.0.5.011 (5.0 SP1).
HotFixes:
Hotfixes are available for both 4.5.x and 5.0.0.x Unity OE versions. Please contact Dell EMC Technical Support or your Authorized Service Representative and quote this Knowledgebase article ID.
Please note that this fix is not included in the Unity OE 5.0 RTS/GA version (5.0.0.0.5.116), and therefore the recommendation would be to upgrade to 5.0 SP1 or later (5.0.1.0.5.011).
Workaround:
If you cannot apply the hotfix, a workaround is to reduce the max Unity SMB dialect to SMB version 3.0.2:
Note: The SMB clients must disconnect all the SMB server shares in order to negotiate the appropriate dialect according to the parameter value. The svc_nas -restart can also be used to force the disconnection of all SMB clients. However this operation restarts also the other NAS server services.
Also, if max dialect 3.1.1 is required, customers can either back-rev their Windows 10 installations to the previous GA version (1803), or wait for Dell EMC to publish the aforementioned hotfix.
This issue is fixed in Unity OE 5.0.1.0.5.011 (5.0 SP1).
HotFixes:
Hotfixes are available for both 4.5.x and 5.0.0.x Unity OE versions. Please contact Dell EMC Technical Support or your Authorized Service Representative and quote this Knowledgebase article ID.
Please note that this fix is not included in the Unity OE 5.0 RTS/GA version (5.0.0.0.5.116), and therefore the recommendation would be to upgrade to 5.0 SP1 or later (5.0.1.0.5.011).
Workaround:
If you cannot apply the hotfix, a workaround is to reduce the max Unity SMB dialect to SMB version 3.0.2:
1. Run the svc_nas command to add the parameter
service@spa:/cores/service# svc_nas ALL -param -f cifs -m smb2.maxDialect -v SMB3.0.2
SPA : done
2. Check to ensure the parameter has been correctly added to the running configuration:
service@spa:/cores/service# svc_nas ALL -param -f cifs -info smb2.maxDialect -v
SPA:
name = smb2.maxDialect
facility_name = cifs
default_value = "" >>>>>>>>>>>>>> The default_value is an empty string "" specifying the MAX dialect supported by the system release (SMB3.1.1).
current_value = SMB3.0.2
configured_value = SMB3.0.2
param_type = global
user_action = none
change_effective = immediate
range = *
description = Specifies the upper SMB2 dialect supported
Note: The SMB clients must disconnect all the SMB server shares in order to negotiate the appropriate dialect according to the parameter value. The svc_nas -restart can also be used to force the disconnection of all SMB clients. However this operation restarts also the other NAS server services.
Also, if max dialect 3.1.1 is required, customers can either back-rev their Windows 10 installations to the previous GA version (1803), or wait for Dell EMC to publish the aforementioned hotfix.
Additional Information
Error in Windows event viewer:
The server does not support any dialect that the client is trying to negotiate, such as the client has SMB2/SMB3 disabled and the server has SMB1 disabled.
Error messages in the Unity c4_safe_ktrace.log
sade:SMB: 3:[nas_serverx] Unrecognized SMB2 negotiate context type 0003
sade:SMB: 3:[nas_serverx] Unrecognized SMB2 negotiate context type 0003
Error in Network traces :
"STATUS_INVALID_PARAMETER"
The server does not support any dialect that the client is trying to negotiate, such as the client has SMB2/SMB3 disabled and the server has SMB1 disabled.
Error messages in the Unity c4_safe_ktrace.log
sade:SMB: 3:[nas_serverx] Unrecognized SMB2 negotiate context type 0003
sade:SMB: 3:[nas_serverx] Unrecognized SMB2 negotiate context type 0003
Error in Network traces :
"STATUS_INVALID_PARAMETER"
Affected Products
Dell EMC Unity FamilyProducts
Dell EMC Unity Family, Dell EMC Unity HybridArticle Properties
Article Number: 000056944
Article Type: Solution
Last Modified: 11 Dec 2025
Version: 4
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