Unable to map SG array on path vmhba. DMA mapping could not be completed DMA Error: Can't meet SG element alignment
Article ID: 397979
Updated On: 05-22-2025
Products
Issue/Introduction
1. Host loses access to volumes
2. VMs running on the datastores lose access to their databases or storage
3. "Lost access to volume" errors follow whichever host the specific VM causing the problem is vMotioned to.
Environment
VMware vSphere ESXi 8.0
Cause
When IOs with large block sizes are issued by virtual machines, there are chances that the IO will get split based on the DMA constraints advertised by the driver and will fail, leading to IOs not making any progress.
VMkernel.log:
Lost access to volume 5fd0####-cec7####-####-20677cd7#### (VMware-Datastore) due to connectivity issues. Recovery attempt is in progress and outcome will be reported shortly.
Lost access to volume 5fd0####-cec7####-####-20677cd7#### (VMware-Datastore) due to connectivity issues. Recovery attempt is in progress and outcome will be reported shortly.
2024-10-03T04:17:36.209Z In(182) vmkernel: cpu2:3077046)qedf:vmhba1:qedfc_eh_abort:3061:Info: IO not found. Returning Success, cmdSN=1e35f2, worldId=2097192
2024-10-03T04:17:36.209Z In(182) vmkernel: cpu24:2302752)qedf:vmhba1:qedfc_eh_abort:3061:Info: IO not found. Returning Success, cmdSN=1e35f2, worldId=2097192
2024-10-03T04:17:36.209Z In(182) vmkernel: cpu24:2302752)ScsiPath: 3787: Opcode 0x2a(0x45b9932f07c0) Unable to map SG array on path vmhba1:C0:T5:L30. Status: DMA mapping could not be completed DMA Error: Can't meet SG element alignment.
2024-10-03T04:17:36.209Z In(182) vmkernel: cpu24:2302752)NMP: nmp_ThrottleLogForDevice:3893: Cmd 0x89 (0x45d999e0a240, 2097192) to dev "naa.600a0##################473325165" on path "vmhba1:C0:T5:L30" Failed:
2024-10-03T04:17:36.209Z In(182) vmkernel: cpu24:2302752)NMP: nmp_ThrottleLogForDevice:3898: H:0x5 D:0x0 P:0x0 . Act:EVAL. cmdId.initiator=0x4307e9761e40 CmdSN 0x1e35f2
2024-10-03T04:17:36.209Z Wa(180) vmkwarning: cpu24:2302752)WARNING: NMP: nmp_DeviceRequestFastDeviceProbe:235: NMP device "naa.600a0##################473325165" state in doubt; requested fast path state update...
2024-10-03T04:17:36.209Z In(182) vmkernel: cpu24:2302752)ScsiDeviceIO: 4656: Cmd(0x45d999edc840) 0xfe, cmdId.initiator=0x4307e9761e40 CmdSN 0x1e35f2 from world 2097192 to dev "naa.600a0##################473325165" failed H:0x5 D:0x0 P:0x0 . Cmd count Active:13
2024-10-21T11:22:22.272Z In(182) vmkernel: cpu3:29408512)ScsiPath: 3787: Opcode 0x2a(0x45b9977a4040) Unable to map SG array on path vmhba2:C0:T7:L32. Status: DMA mapping could not be completed DMA Error: Can't meet SG element alignment.
2024-10-21T11:22:22.272Z In(182) vmkernel: cpu3:29408512)ScsiPath: 3787: Opcode 0x2a(0x45b9977a4040) Unable to map SG array on path vmhba2:C0:T7:L32. Status: DMA mapping could not be completed DMA Error: Can't meet SG element alignment.
2024-10-21T11:22:22.272Z In(182) vmkernel: cpu3:29408512)ScsiPath: 3787: Opcode 0x2a(0x45b9977a4040) Unable to map SG array on path vmhba2:C0:T7:L32. Status: DMA mapping could not be completed DMA Error: Can't meet SG element alignment.
2024-10-21T11:22:22.272Z In(182) vmkernel: cpu3:29408512)ScsiPath: 3787: Opcode 0x2a(0x45b9977a4040) Unable to map SG array on path vmhba2:C0:T7:L32. Status: DMA mapping could not be completed DMA Error: Can't meet SG element alignment.
vobd.log:
2024-10-03T04:14:25.522Z In(14) vobd[2097573]: [vmfsCorrelator] 5023398263437us: [esx.problem.vmfs.heartbeat.recovered] 5fd008d5-########-####-20677cd7b030 VMware-Datastore
2024-10-03T04:17:37.209Z In(14) vobd[2097573]: [vmfsCorrelator] 5023532722987us: [vob.vmfs.heartbeat.timedout] 5fd008d5-########-####-20677cd7b030 VMware-Datastore
2024-10-03T04:17:37.209Z In(14) vobd[2097573]: [vmfsCorrelator] 5023589950608us: [esx.problem.vmfs.heartbeat.timedout] 5fd008d5-########-####-20677cd7b030 VMware-Datastore
2024-10-03T04:17:37.209Z In(14) vobd[2097573]: [vmfsCorrelator] 5023532723019us: [vob.vmfs.heartbeat.timedout] 5fd008d5-########-####-20677cd7b030 VMware-Datastore
2024-10-03T04:17:37.210Z In(14) vobd[2097573]: [vmfsCorrelator] 5023589950955us: [esx.problem.vmfs.heartbeat.timedout] 5fd008d5-########-####-20677cd7b030 VMware-Datastore
2024-10-03T04:17:37.311Z In(14) vobd[2097573]: [vmfsCorrelator] 5023532825647us: [vob.vmfs.heartbeat.recovered] Reclaimed heartbeat for volume 5fd008d5-########-####-20677cd7b030 (VMware-Datastore): [Timeout] [HB state abcdef02 offset 3244032 gen 270779 stampUS 5023532825154 uuid 66b17397-########-####-5ced8c07bdb0 jrnl <FB 5> drv 24.82]
2024-10-03T04:17:37.311Z In(14) vobd[2097573]: [vmfsCorrelator] 5023590052109us: [esx.problem.vmfs.heartbeat.recovered] 5fd008d5-########-####-20677cd7b030 VMware-Datastore
Resolution
To resolve this issue, disable the config option /Scsi/ScsiPathSplitUseSimpleCloneBuffer using the following commands.
1. List the configuration option
esxcli system settings advanced list -o /Scsi/ScsiPathSplitUseSimpleCloneBuffer Path: /Scsi/ScsiPathSplitUseSimpleCloneBuffer Type: integer Int Value: 1 <<<<==== The default value of this config option Default Int Value: 1 Min Value: 0 Max Value: 1 String Value: Default String Value: Valid Characters: Description: Use simple clone buffers to split IOs at path layer whenever possible. Host Specific: false Impact: none
2. Set the configuration option to 0
esxcli system settings advanced set -o /Scsi/ScsiPathSplitUseSimpleCloneBuffer -i 0
3. Verify the configuration option
esxcli system settings advanced list -o /Scsi/ScsiPathSplitUseSimpleCloneBuffer Path: /Scsi/ScsiPathSplitUseSimpleCloneBuffer Type: integer Int Value: 0 <<<<==== This value is reset to 0 after step #2 Default Int Value: 1 Min Value: 0 Max Value: 1 String Value: Default String Value: Valid Characters: Description: Use simple clone buffers to split IOs at path layer whenever possible. Host Specific: false Impact: none
Additional Information
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