Sun Storage 7000 Unified Storage System: SMB clients may experience disconnects when connecting to a second share from the same server but by a different DNS name

Asset ID:	1-72-1510547.1
Update Date:	2015-11-05
Keywords:

Solution Type Problem Resolution Sure

Solution 1510547.1 : Sun Storage 7000 Unified Storage System: SMB clients may experience disconnects when connecting to a second share from the same server but by a different DNS name

Applies to:

Sun Storage 7210 Unified Storage System - Version All Versions and later
Sun Storage 7110 Unified Storage System - Version All Versions and later
Sun ZFS Storage 7420 - Version All Versions and later
Sun ZFS Storage 7320 - Version All Versions and later
Sun ZFS Storage 7120 - Version All Versions and later
7000 Appliance OS (Fishworks)

Symptoms

A client accessing a share from a ZFS Storage Appliance via SMB may in certain circumstances experience a disconnect from other SMB shares from the same appliance.

The appliance will have more than one alias set up for it in DNS.

To discuss this information further with Oracle experts and industry peers, we encourage you to review, join or start a discussion in the My Oracle Support Community - Disk Storage ZFS Storage Appliance Community

Cause

This is actually the correct behaviour.

Each SMB connection is associated with a virtual circuit (VC) number. When an SMB server receives a VC number of zero in a SessionSetupX request it should disconnect all previous sessions from that client. A client connection is based on the IP addresses of the client and server. When aliases are created in DNS for an SMB server, the SMB client is unaware that the server has multiple names and connects to each name using VC 0. This causes each connection to one name to disconnect sessions created via another name.

See Bug 15691954 for further details.

Also see Bug 15790539 for details on the fix for the appliance.

Solution

In order to avoid these disconnects due to receiving multiple VC=0 sessions from the same client, it is possible to turn off the VC=0 check.

To do this first upgrade to appliance software version 2011.04.24.4.2.

Since there are as yet no settings in the CLI or BUI to allow this setting to be user configurable it will be necessary to contact Oracle Support to get workflows that will allow the disabling of the VC=0 check, and if necessary the re-enabling of the VC=0 check. Please raise an SR for this.

After upgrading to 2011.04.24.4.2 and receiving the workflows, upload the workflows to the BUI using

Maintenance -> WORKFLOWS

Click "+" to upload a new workflow

Browse to the location on your local system where the workflows were saved, select the files and then upload.

Once the file is visible in the list of workflows double-click it to run.

Choose disable_vczero.akwf to turn off the check and allow multiple connections from the same client with vc=0

Choose enable_vczero.akwf to turn the check back on if needed.

In forthcoming versions of the appliance software the option to configure the VC=0 check will be available via the BUI or CLI and the workflows will no longer be needed.

The workflows are available from the Amber Road Support wiki please contact the NAS team, if you do not have access.

Disable vc=zero check

Enable vc=0 check

References

Amber Road Support Wiki Workflows: https://stbeehive.oracle.com/teamcollab/overview/AmberRoadSupport#Workflows
<BUG:15691954> - SUNBT7012679-SOLARIS_11 CONFIGURABLE BYPASS FOR VCNUMBER ZERO
<BUG:15785456> - SUNBT7161291 WINDOWS 7 CLIENTS CAN'T ACCESS 2ND SMB SHARE MAPPED FROM SAME APPLI
<BUG:15790539> - SUNBT7167443 APPLIANCE NEEDS TO SUPPORT CONFIGURABLE BYPASS FOR VCNUMBER ZERO

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