This document provides an in-depth guide on NFS and iSCSI Multipathing in vSphere, covering path selection, configuration, best practices, redundancy measures, and troubleshooting. It also includes CLI commands for configuration.

Key Sections & Summaries

1. Path Selection

• NFS 4.1 clients use a Round-Robin method to select paths from active ones.
• If a path goes down, it is removed until connectivity is restored.

2. Multipathing Configuration

• Before configuring multipathing, verify if the NFS server supports multiple paths.
• Multiple paths must be specified at volume mount.
• Additional paths require unmounting and remounting.

Paths in the Same Subnet

• If two paths share the same subnet, ESXi creates independent connections using the vmkernel portgroup IP.
• ESXi chooses only one source IP for connections, even if multiple are configured.

CLI Command for Same Subnet Configuration:

#esxcli storage nfs41 -H 192.168.1.30, 192.168.1.31 -s /mnt/share1 -v nfs41share1

Best Practice: Configure NIC Teaming using IP Hash Load-Balancing.

Paths in Different Subnets

• Multiple vmkernel portgroups are configured for different subnets.
• Ensures better redundancy and bandwidth utilization.

Example Configuration:

• 192.168.1.y → vmk1 (same subnet as vmk1).
• 192.168.2.y → vmk2 (same subnet as vmk2).

CLI Command for Different Subnet Configuration:

#esxcli storage nfs41 -H 192.168.1.101, 192.168.3.101 -s /share2 -v nfs41Share2

Best Practice: Use separate virtual switches for each subnet to improve redundancy.

3. Avoiding Single Points of Failure

• NIC Teaming provides first-level redundancy.
• Physical Switch Redundancy: Use multiple LAN switches to prevent single points of failure.

Viewing Multipath Connections

• Use vsish utility to check NFS multipath connections.

#esxcli storage nfs41 list

Sample Output:

NFSv4.1 Connection Info {

network Address:tcp:192.168.1.101.8.1

state:NFS41_S_CONN_UP

}

4. Configuring iSCSI Storage

• Step-by-step walkthrough on configuring iSCSI storage in ESXi and vSphere Web Client.
• Steps include:
  1. Adding VMkernel Adapters.
  2. Configuring NIC Teaming & Failover.
  3. Adding an iSCSI Adapter.
  4. Connecting to iSCSI Storage Arrays.
  5. Scanning for new LUNs and creating VMFS Datastores.

CLI Command to Add iSCSI Targets:

#esxcli iscsi adapter discovery sendtarget add -A vmhba33 -a 192.168.1.50

Conclusion

• The document provides best practices and CLI commands for configuring NFS & iSCSI multipathing.
• NIC Teaming, Subnet Configuration, and Redundancy measures improve storage performance and failover reliability.
• iSCSI walkthrough ensures proper connectivity and high availability.