🔥 Advanced ESXi Troubleshooting Based on Specific Technologies

🔹 Hardware-Specific Issues (HPE, Dell, Cisco UCS)

24. ESXi Host Fails to Boot After Firmware Update (HPE/Dell/Cisco UCS)

Scenario:

• After updating the BIOS, iLO (HPE), iDRAC (Dell), or CIMC (Cisco UCS), the ESXi host no longer boots.
• The host shows a “Purple Screen of Death (PSOD)” or gets stuck during boot.

Solution Steps:

1. Check Compatibility of Firmware with ESXi Version
   • Ensure the new firmware is compatible with your ESXi version using VMware’s HCL (Hardware Compatibility List):
     👉 VMware HCL
2. Check Boot Order in BIOS
   • Ensure UEFI/Legacy BIOS settings did not change during the update.
3. Roll Back to Previous Firmware (If Needed)
   • HPE: Use iLO → Firmware Rollback.
   • Dell: Use iDRAC Lifecycle Controller.
   • Cisco UCS: Use CIMC to restore firmware version.
4. Check ESXi Secure Boot Status bashCopyEditesxcli system settings encryption get
   • If Secure Boot is enabled, disable it in BIOS/UEFI and retry.

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25. ESXi Host Reports “No Compatible NIC Found” on HPE/Dell Servers

Scenario:

• After installing ESXi on an HPE/Dell server, no network adapters are detected.

Solution Steps:

1. Check if the NIC is on VMware HCL
   • Some newer HPE FlexFabric, Dell X710/X722 NICs require additional drivers.
2. Check Available Network Adapters in ESXi bashCopyEditesxcli network nic list
   • If no adapters are listed, drivers are missing.
3. Manually Install NIC Drivers (If Needed)
   • Download drivers from VMware or vendor site (HPE, Dell, Cisco).
   • Upload the driver to ESXi and install using: bashCopyEditesxcli software vib install -v /vmfs/volumes/datastore1/<driver>.vib --no-sig-check
4. Reboot and Verify NIC Detection bashCopyEditesxcli network nic list

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🔹 Storage-Specific Issues (vSAN, iSCSI, FC, NFS)

26. vSAN Cluster Shows “Absent” or “Degraded” State

Scenario:

• vSAN Objects become “Absent” or “Degraded”.
• VM performance slows down drastically.

Solution Steps:

1. Check vSAN Cluster Health bashCopyEditesxcli vsan health cluster get
2. Verify Disk Groups and Rebuild Status bashCopyEditesxcli vsan storage list
3. Check if vSAN Objects Are Being Rebuilt bashCopyEditesxcli vsan debug object list
4. If vSAN Disks Are Missing, Reclaim Them bashCopyEditesxcli vsan storage add -d naa.xxxxxxx

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27. iSCSI Multipath Not Working – Only One Path Active

Scenario:

• iSCSI storage shows only one path instead of multiple paths.

Solution Steps:

1. Verify Multipath Configuration bashCopyEditesxcli storage nmp device list
2. Check iSCSI Sessions bashCopyEditesxcli iscsi session list
3. Manually Add Missing iSCSI Targets bashCopyEditesxcli iscsi adapter discovery sendtarget add -a <Storage_IP>
4. Change Path Selection Policy to Round Robin bashCopyEditesxcli storage nmp satp set -s VMW_SATP_DEFAULT_AA -P VMW_PSP_RR
5. Rescan the Storage Adapters bashCopyEditesxcli storage core adapter rescan --all

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28. NFS Datastore Disappears After ESXi Reboot

Scenario:

• An NFS datastore becomes unavailable after rebooting ESXi.

Solution Steps:

1. Check If NFS Mount Is Still Available bashCopyEditesxcli storage nfs list
2. Manually Re-Mount the NFS Datastore bashCopyEditesxcli storage nfs add -H <NFS_IP> -s /nfs_share -v NFS_Datastore
3. Verify NFS Firewall Rules bashCopyEditesxcli network firewall ruleset list | grep nfs
4. Restart NFS Client Services bashCopyEdit/etc/init.d/nfs restart

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🔹 Advanced Network Issues (NSX-T, VLAN, LACP, VXLAN)

29. NSX-T Logical Switch Shows “Down” State

Scenario:

• NSX-T Logical Switch fails and VMs lose connectivity.

Solution Steps:

1. Check NSX-T Transport Node Status bashCopyEditget transport-node
2. Restart NSX-T Services on ESXi bashCopyEdit/etc/init.d/nsx-proxy restart /etc/init.d/nsx-mpa restart
3. Verify VXLAN Tunnel Status bashCopyEditesxcli network vswitch dvs vmware vxlan network list
4. Reapply NSX-T Configuration bashCopyEditnsxcli -c "apply nsx config"

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30. VLANs Not Passing Through vSwitch (802.1Q Trunk Issues)

Scenario:

• VLAN traffic is not reaching VMs despite correct VLAN tagging.

Solution Steps:

1. Verify Port Group VLAN ID on ESXi bashCopyEditesxcli network vswitch standard portgroup list
2. Ensure Physical Switch is Configured for VLAN Trunking
   • On Cisco Switch: bashCopyEditshow interface trunk
3. Check if VLANs Are Blocked by Security Policies bashCopyEditesxcli network vswitch standard policy security get
4. Enable VLAN Tagging on vSwitch bashCopyEditesxcli network vswitch standard portgroup set -p "VM Network" -v 10

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31. LACP (Link Aggregation) Fails Between ESXi and Physical Switch

Scenario:

• LACP bond between ESXi and the physical switch fails or shows only one active link.

Solution Steps:

1. Check if LACP is Enabled on the vSwitch bashCopyEditesxcli network vswitch dvs vmware lacp status
2. Verify LACP Mode on Physical Switch
   • Cisco Switch: bashCopyEditshow etherchannel summary
3. Restart ESXi Network Services bashCopyEdit/etc/init.d/networking restart
4. Manually Reconfigure LACP on ESXi bashCopyEditesxcli network vswitch dvs vmware lacp set --enable