When implementing enterprise storage with Fibre Channel (FC), the traditional architecture involves FC switches to create a Storage Area Network (SAN) fabric. However, in smaller deployments like your 3-node VMware cluster with an HP MSA 2040, direct attachment might be technically feasible.

The HP MSA 2040's 8 FC ports support point-to-point connections. Each ESXi host with dual-port HBAs can establish two independent paths to the SAN:

# Typical HBA configuration in ESXi (example)
esxcli storage core adapter list
# Should show your QLogic/Emulex HBA ports

vMotion and HA will function with direct FC connections, but with important considerations:

• No automatic path failover between servers (unlike switched fabric)
• Each LUN must be manually mapped to all hosts
• Zoning must be properly configured on the MSA array

For a 3-host cluster, you'd configure your MSA ports as follows:

# MSA 2040 zoning example for 3 hosts
msa# storage array create zone --name esxi01_zone --port 0 --hba 21:00:00:24:ff:31:6e:50
msa# storage array create zone --name esxi01_zone_alt --port 1 --hba 21:00:00:24:ff:31:6e:51
# Repeat for other hosts

Without FC switches:

• No fabric-based multipathing (like FCP_AL)
• Each server has dedicated bandwidth but no cross-server pathing
• Maintenance becomes more complex during array updates

Before committing to direct connection, consider:

1. Used enterprise FC switches (Brocade 300/6505)
2. iSCSI with 10Gbps networking
3. SAS-attached storage for small clusters

If proceeding with direct FC:

# ESXi host storage configuration checklist
1. Verify HBA driver version
2. Configure persistent binding:
esxcli storage nmp device set --device naa.600508b4000156d70000000000000000 --psp VMW_PSP_FIXED
3. Set SATP rule for MSA:
esxcli storage nmp satp add --satp VMW_SATP_ALUA --device naa.600508b4000156d70000000000000000

While direct FC works for small clusters, scalability limitations emerge when:

• Adding more than 4-5 hosts
• Implementing stretched clusters
• Needing advanced SAN services (like NPIV)

Connecting Fibre Channel HBAs directly to an HP MSA 2040 SAN without switches is technically possible through point-to-point (P2P) FC topology. The MSA 2040's 8 FC ports support both switched fabric (F_Port) and point-to-point (P_Port) modes. When directly connected:

# Example ESXi host SAN configuration (direct connection)
esxcli storage core adapter list | grep "HBA Model"
esxcli storage nmp device list | grep "MSA2040"
esxcli storage nmp satp rule add -s VMW_SATP_DEFAULT_AA -d MSA2040 -o enable_alua

For a 3-node ESXi cluster with direct FC connections:

• Each host needs dual-port FC HBAs (QLogic or Emulex)
• MSA 2040 requires proper zoning configuration (even without switches)
• ALUA (Asymmetric Logical Unit Access) must be enabled

Direct FC connections impact cluster operations differently:

# Sample PowerCLI to verify HA configuration
Get-Cluster "YourCluster" | Select-Object -Property HAEnabled,HAAdmissionControlEnabled
Get-VMHost | Get-VMHostHba -Type FibreChannel | Format-Table Device,Status,Model

Key observations from production deployments:

• vMotion works but requires identical storage visibility across hosts
• HA failover may experience longer detection times (adjust das.failureDetectionTime)
• Storage DRS becomes less effective without shared switch visibility

For smaller budgets, consider this mixed approach:

# Using one FC switch for critical paths + direct connections
# Primary path: FC switch (for HA heartbeat)
# Secondary path: Direct SAN connection (for data)
esxcli storage nmp path set -P VMW_PSP_RR -A VMW_SATP_ALUA -U "naa.600508b4000c4d3d0000000000000000"