Dell EMC Unity: Using Continuous Availability when upgrading to version 5.1.2 may cause SP panics (User Correctable)

Following the upgrade, SPs may panic and reboot into service mode. Users are unable to remove the SPs from service mode.

The issue is related to the Continuous Availability feature of SMB. It was found that in a few cases, customers who have Continuous Availability that is selected on their SMB shares, and who had high numbers of open file handles on those shares (greater than 97 open handles) led to a new variable (phMaxTimeout) having an unexpectedly high value. This induces the panic and service mode.

Fix:

Upgrade to Dell EMC Unity Operating Environment (OE) version 5.1.3 to fix this issue.

Workaround:

If you have already upgraded and have encountered this issue, contact Dell EMC Technical Support or your Authorized Service Provider and quote this Knowledgebase article ID.

If you have not upgraded to version 5.1.2, and you cannot upgrade to 5.1.3, you must disable Continuous Availability on all your SMB shares before upgrading.

1. In Unisphere, select the STORAGE heading and click File. Choose the SMB Shares tab.
2. Click each SMB share and select Properties (click the pencil icon after selecting the share).
3. In the Properties dialog, click the Advanced tab.
4. Ensure that Continuous Availability is off.

You can also check and disable Continuous Availability using uemcli with the below commands:

• uemcli -no /stor/prov/fs/cifs show -filter "Name","Availability enabled" -output csv
  uemcli -no /stor/prov/fs/cifs -id <share id> set -enableContinuousAvailability no

Disable Durable handles (DH) for all VDMs with the below command:

• svc_nas ALL -param -f cifs -m smb2.defaultFdhv2Timeout -v 0