When migrating from a VMware vSphere environment to a Hyper-V Cluster with a Dell EqualLogic PS6100 storage array, network configuration is crucial for seamless integration and performance stability. This technical guide will address critical aspects of integrating EqualLogic storage with a new infrastructure during a subnet migration.
Understanding Network Portal and Portal Groups
The concept of a Network Portal and Portal Groups is essential in iSCSI environments. A Network Portal is a component that has a TCP/IP address and is used for iSCSI node connections. Portal Groups consist of multiple Network Portals within a network entity. They allow for coordinated sessions across various portals, enhancing connection robustness and throughput.
EqualLogic Group IP Address
The EqualLogic Group IP Address is used as the iSCSI discovery address. If modified, it can disrupt current iSCSI connections. Ensure that necessary adjustments are made in initiator configurations when changes occur. According to Dell’s [Group Manager](https://psonlinehelp.equallogic.com/en/V6.0/groupmanager.htm) documentation, any change to the group IP address will disconnect all iSCSI sessions, which must be carefully managed to prevent disruption.
Subnet Migration Strategy
Challenges with Mixed Subnets
During a migration where the storage network spans multiple subnets, issues arise when the Group IP Address is configured on a previous subnet. This mismatch can result in initiators failing to establish connections due to discrepancies between the iSCSI target discovery process and actual network portal accessibility.
Managing Dual Subnet Configurations
To mitigate potential disruptions:
- Ensure that each storage network NIC configuration aligns with the correct VLAN and subnet. This involves configuring unused NICs to facilitate dual subnet operation temporarily.
- Perform thorough testing with a single non-critical Hyper-V host to verify connectivity before expanding the setup.
Connecting iSCSI Initiators
When connecting Microsoft iSCSI Initiator to EqualLogic storage targets, failures often occur if the Group IP Address does not match the desired subnet:
- Verify that the iSCSI target portals are configured correctly on the initiator side, ensuring IP addresses match those available on the newly configured subnet.
- Check event logs for ISCSIPrt event IDs, such as 1 and 70, which may indicate connectivity issues.
Adjusting EqualLogic Network Configuration
Changing the EqualLogic Group IP Address to the new subnet should be considered, albeit with caution:
- Prepare for a controlled environment outage if opting to alter the Group IP Address, as this change will disconnect existing storage sessions.
- To minimize downtime, schedule adjustments during off-peak hours, and ensure all necessary backups and failover procedures are in place.
Conclusion
While implementing a migration strategy that avoids immediate cutover can mitigate risks, understanding and balancing the limitations and capabilities of your network setup is crucial. By carefully planning the configuration of network portals and group IPs, you can ensure a smoother transition for your storage network in a multi-subnet environment.
For further reading and best practices, consult the official [Dell EqualLogic Documentation](https://psonlinehelp.equallogic.com/en/V6.0/groupmanager.htm) and related guidelines.
