Error: "Cannot change the host configuration. Failed to update disk partitions for /vmfs/devices/disks/naa.600a09803xxxxxxxxxxxxxxxxx" while creating iSCSI datastore from LUN.

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:

Unable to create iSCSI datastore as it fails with the below error 

"Cannot change the host configuration. Failed to update disk partitions for /vmfs/devices/disks/naa.600a09803xxxxxxxxxxxxxxxxx"

     

Confirm the LUN is a raw LUN and there is no existing VMFS partition on the device. 
For example:
partedUtil getptbl /vmfs/devices/disks/naa.<ID>
unknown
2673493 255 63 42949672960

The vmkernel.log shows iSCSI connection flapping between 'offline' and 'online' while creating a VMFS datastore

/var/run/log/vmkernel.log

2025-04-11T16:46:51.356Z Wa(180) vmkwarning: cpu23:3668429)WARNING: iscsi_vmk: iscsivmk_StopConnection:736: vmhba64:CH:3 T:0 CN:0: iSCSI connection is being marked "OFFLINE" (Event:4)

2025-04-11T16:46:51.356Z Wa(180) vmkwarning: cpu23:3668429)WARNING: iscsi_vmk: iscsivmk_StopConnection:740: Sess [ISID: 00023d000004 TARGET: iqn.1992-08.com.test:sn.d92d###########################:vs.24 TPGT: 443 TSIH: 0]

2025-04-11T16:46:51.356Z Wa(180) vmkwarning: cpu23:3668429)WARNING: iscsi_vmk: iscsivmk_StopConnection:741: Conn [CID: 0 L: ###.###.###.###:21242 R: ###.###.###.###:3260]

2025-04-11T16:46:51.362Z In(182) vmkernel: cpu23:3668186)NMP: nmp_ThrottleLogForDevice:3893: Cmd 0x2a (0x45c9811f6400, 3972496) to dev "naa.600a09803#################" on path "vmhba64:C3:T0:L0" Failed:

2025-04-11T16:46:51.362Z In(182) vmkernel: cpu23:3668186)NMP: nmp_ThrottleLogForDevice:3898: H:0x2 D:0x0 P:0x0 . Act:EVAL. cmdId.initiator=0x4309749d6900 CmdSN 0x3

2025-04-11T16:46:51.362Z Wa(180) vmkwarning: cpu23:3668186)WARNING: NMP: nmp_DeviceRequestFastDeviceProbe:235: NMP device "naa.600a09803#################" state in doubt; requested fast path state update...

2025-04-11T16:46:51.362Z In(182) vmkernel: cpu23:3668186)ScsiDeviceIO: 4619: Cmd(0x45c9811f6400) 0x2a, CmdSN 0x3 from world 3972496 to dev "naa.600a09803#################" failed H:0x2 D:0x0 P:0x0

2025-04-11T16:46:51.897Z Wa(180) vmkwarning: cpu104:2098032)WARNING: VMW_SATP_ALUA: satp_alua_getTargetPortInfo:190: Could not get page 83 INQUIRY data for path "vmhba64:C3:T0:L0" - Transient storage condition, suggest retry (195887294)

2025-04-11T16:46:51.934Z Wa(180) vmkwarning: cpu23:3668186)WARNING: NMP: nmp_DeviceRequestFastDeviceProbe:235: NMP device "naa.600a09803#################" state in doubt; requested fast path state update...

2025-04-11T16:46:55.144Z Wa(180) vmkwarning: cpu23:3668429)WARNING: iscsi_vmk: iscsivmk_StartConnection:918: vmhba64:CH:3 T:0 CN:0: iSCSI connection is being marked "ONLINE"

Environment

VMware vSphere ESXi 7.x
VMware vSphere ESXi 8.x

Cause

The MTU misconfiguration between the VMkernel adapters, physical NICs, and physical switches will result in connectivity issues and prevents the datastore creation.

MTU (Maximum Transmission Unit) configuration should be consistent across VMkernel adapters, physical NICs, and switches.

Resolution

Fix the MTU settings to match with physical network and on vSwitch to resolve this issue.

You may refer the documentation iSCSI and Jumbo Frames configuration on VMware ESXi/ESX for more information on setting and verifying MTU settings.

Verify MTU is showing up on both nic's {if the vSwitch uses two nic's} and correct Vlan id is tagged to the vmnic.