When managing Dell EqualLogic storage systems, understanding controller failover and the implications on network connectivity is essential for ensuring consistent and reliable performance. This guide synthesizes expert advice on handling active/passive controller configurations within EqualLogic arrays.
Controller Failover and Configuration
EqualLogic storage systems utilize an active/passive controller setup to maintain high availability. During normal operation, the active controller manages all data traffic, while the passive controller stands by to take over if the active controller fails. Failover processes can be tested manually or automatically in the case of a hardware issue.
Manual Failover Testing
In some scenarios, it is beneficial to test the failover process prior to deploying a storage array in a production environment. To simulate a failover:
- Unplug the network connection (RJ45) from the active controller. This action will prompt the passive controller to assume the workload.
- Monitor the switchover process to verify that network traffic redirects seamlessly and without disruption.
Testing in this manner can reveal configuration issues that may cause downtime during unexpected failover events, offering an opportunity to address them proactively.
Automatic Failover Behavior
In an automatic failover event, such as a hardware failure, the passive controller will immediately take over operation. It’s important that the iSCSI configurations on connected hosts are set to handle these transitions smoothly. In scenarios where the active controller comes back online, it may be necessary to direct network traffic back to the original configuration. This ensures that the system operates with the intended performance and redundancy.
Best Practices for Controller Management
The following guidelines help ensure the stability and efficiency of Dell EqualLogic storage systems:
- Consistent Firmware Updates: Regularly update firmware on both active and passive controllers to maintain compatibility and optimal performance. Refer to the official Dell EqualLogic support page for the latest updates.
- Network Configuration: Ensure that network settings, such as MTU sizes and VLAN configurations, are consistent across both controllers to facilitate smooth failover transitions.
- iSCSI Target Management: Regularly verify that iSCSI targets are correctly configured and that redundancy paths are recognized by connected hosts.
Understanding and implementing these recommendations will improve the reliability and performance of your EqualLogic environment, providing a robust foundation for enterprise storage solutions.
