Seamless Failover

Introduction

Seamless SMB Failover is an optional feature for Access Zone and IP Pool failover. It helps reduce client disruption by managing SMB sessions during failover. Clients reconnect automatically to shared storage without needing to remount shares.

Administrators can also check how many clients are connected to each Access Zone or IP Pool before starting a failover. This makes planning easier and supports more controlled operations.

This document outlines the requirements, configuration, how the feature works, and where to find related guides.

Requirements

Seamless SMB Failover is available in version 2.12 and later. For details about new features in this release, see What's New in 2.12?

If you've recently upgraded, you will need to add the following command to the PowerScale sudoers file:

eyeglass ALL=(ALL) NOPASSWD: /usr/bin/isi_for_array netstat*

Failover must be configured for either Access Zones or IP Pools. Refer to the following guides:

• Access Zone Failover Configuration
• IP Pool Failover Configuration

A working SMB environment is required, along with DNS resolution for client reconnection.

Configuration Steps

No additional setup is required to enable Seamless SMB Failover. Once the system version and permissions are in place, the feature is active by default.

How Seamless SMB Failover Works

Seamless SMB Failover manages client reconnection by identifying and terminating active SMB sessions tied to the Access Zone or IP Pool being failed over. This triggers clients to reconnect without requiring manual action.

1. Session Identification

   Active SMB client connections are identified using netstat.

2. Session Termination

   During failover, the Disaster Recovery appliance issues a REST API request to disconnect active SMB sessions tied to the affected Access Zone or IP Pool.

3. Client Reconnection

   After the session is ended, the client automatically retries the connection. This triggers a DNS lookup, which returns the new IP address of the failed over pool, allowing the SMB session to be re-established.

Operations

Check Connected Clients

A Connected Clients column appears in both the DR Assistant Failover Wizard and the DR Dashboard readiness table.

This column shows the number of active SMB clients connected to each Access Zone or IP Pool.

Selecting Check runs a query to retrieve the current client count. The value can be refreshed as needed to support planning before initiating a failover.

See Also

• Check Readiness Before Failover

  Learn how to assess readiness for Access Zone and IP Pool failover. This includes checking connected SMB clients to support better timing and planning.

• Execute a Failover

  Instructions for running an Access Zone or IP Pool failover using the DR Assistant Failover Wizard, with support for Seamless SMB Failover.