VMkernel log spams 'Failed to probe the VMFS header'.

Products

• VMware vSphere ESXi

Issue/Introduction

This document's purpose is to inform the CXS engineers on the impact of VMFS probe failure messages.

Symptoms:

• vmkernel log sporadically spams messages similar to following:

xxxx-xx-xxT04:39:02.105Z cpu34:2100630)LVM: 7053: Failed to probe the VMFS header of naa.################################:1 due to No filesystem on the device
xxxx-xx-xxT04:39:02.113Z cpu34:2100630)LVM: 7053: Failed to probe the VMFS header of naa.################################:1 due to No filesystem on the device
xxxx-xx-xxT04:39:02.125Z cpu34:2100630)LVM: 7053: Failed to probe the VMFS header of naa.################################:1 due to No filesystem on the device
xxxx-xx-xxT04:39:11.387Z cpu34:2100630)LVM: 7053: Failed to probe the VMFS header of naa.################################:1 due to No filesystem on the device
xxxx-xx-xxT04:39:11.390Z cpu34:2100630)LVM: 7053: Failed to probe the VMFS header of naa.################################:1 due to No filesystem on the device
xxxx-xx-xxT04:39:11.393Z cpu34:2100630)LVM: 7053: Failed to probe the VMFS header of naa.################################:1 due to No filesystem on the device
xxxx-xx-xxT04:39:11.396Z cpu34:2100630)LVM: 7053: Failed to probe the VMFS header of naa.################################:1 due to No filesystem on the device
xxxx-xx-xxT04:39:11.409Z cpu34:2100630)LVM: 7053: Failed to probe the VMFS header of naa.################################:1 due to No filesystem on the device

 

• Mostly the symptom shows right after a host acknowledges VMFS volume.

Environment

VMware vSphere ESXi 7.0.x

Cause

A host initiates header probing on any VMFS volume it encounters. If a volume is consisted of multiple extents, the probing is done only on the first extent since it is the location where a filesystem header resides.
The above log spamming might happen when a hosts initiates said header probing on every physical extents within a volume.

Resolution

To check whether the probe failure is occurring on the first extent or not, open CLI (SSH or DCUI) to the host and enter following script:

for dir in $(find /vmfs/volumes/ -type l -mindepth 1 -maxdepth 1 -exec echo {} \;); do res=$(vmkfstools -P -v 10 "$dir" 2> /dev/null | grep -A1 "Partitions spanned" | tail -n1 | sed -e 's/[[:space:]]//g'); echo "$res" | xargs -I {} grep -q {} /var/run/log/vmkernel.* | grep "Failed to probe the VMFS" && echo "Physical extent $res of datastore $(basename $dir) is missing LVM magic!" || echo "Physical extent $res of datastore $(basename $dir) has LVM metadata intact"; done

Additional Information

Impact/Risks:
If the host does not show any particular storage issues, the symptom is mostly benign.