vSAN Health Service - Physical Disk Health

Products

VMware vSAN

Issue/Introduction

This article explains the Physical disk Health - Overall Disks Health check in the vSAN Health Service and provides details on why it might report an error.

Environment

VMware vSAN 6.5.x
VMware vSAN 6.0.x
VMware vSAN 8.0.x
VMware vSAN 7.0.x

Resolution

Q: What does the Physical Disk Health - Overall Disks Health check do?

Checks the physical disk operation status for all hosts in the vSAN cluster.

Q: What does it mean when it is in an error state?

If this check fails, the disk cannot be used by vSAN or vSAN Direct anymore with the possible reasons including the physical disk damage, the issue in reading the disk metadata, the vSAN software issue preventing it to use this disk or the disk is in read-only mode.

Q: What does it mean when the operational state is Impending permanent disk failure?

Dying Disk Handling (DDH) in vSAN continuously monitors the health of disks and disk groups in order to detect an impending disk failure or a poorly performing disk group. When such conditions are detected, vSAN marks the disk or disk group as unhealthy and might trigger data evacuation from the affected disk or disk group. Such disks and disk groups display an operational state of Impending permanent disk failure. For more information, see Dying Disk Handling (DDH) in vSAN 6.6 (2148358).

Note: This state is not available for vSAN Direct.

Q: How does one troubleshoot and fix the error state?

You need to examine the information displayed as part of the health check.

For example:

Is the disk offline or permanent failure indicating there is physical disk damage?
Is it an issue when trying to read the metadata of the drive? This implies that the drive is offline and unavailable for use.
Is it the vSAN software state that is the root cause, which in all likelihood will impact all of the disks on this host?
Is the disk set to read-only mode? In this case please contact VMware support to help unset the disk read-only mode.

Each of these individual checks must be considered to determine the corrective course of action. Some of the checks imply that the drive is offline, others imply that the drive is still online, but some corrective action might be needed.

Note: From VMware vSAN 6.5 Update 2, Physical disk overview is rebranded as Operation Health.

Additional Information

For more information on collecting VMware vSAN logs, see Collecting vSAN support logs and uploading to VMware (2072796).

For more information about how vSAN handles dying disks, see Dying Disk Handling (DDH) in vSAN 6.6 (2148358).

For more information about disk failures in a vSAN cluster with deduplication, see Identifying specific disk failure in a vSAN deduplication cluster (2149067).

Also, see: