Unable to Enter Maintenance Mode on Host Due to Internal vSAN Error

Products

• VMware vSAN 8.x
• VMware vSphere ESXi

Issue/Introduction

Symptoms 

While entering the host into Maintenace mode it failed with an error at 87%  as below 

General vSAN error. Failed to enter or exit maintenance mode due to an internal vSAN error. Retry operation.

While performing a vSAN cluster health test, a primary stat collection error was observed.

Few Objects were showing inaccessible state 

Environment

VMware vSAN 8.x

Cause

Advanced setting /VSAN/DOMPauseAllCCPs is set to 1 on one or more hosts in the cluster.

This advanced setting is used for vSAN cluster shutdown for data protection, as setting this option to 1 pauses all vSAN components operations on a host, effectively making objects owned by that host inaccessible.
In other words, the vSAN objects are not available to the compute resources, resulting in inaccessible VMs in the inventory

Resolution

Run command "esxcfg-advcfg -g /VSAN/DOMPauseAllCCPs" on  all hosts to get the current value:

[root@esxi#:~] esxcfg-advcfg -g /VSAN/DOMPauseAllCCPs

Value of DOMPauseAllCCPs is 1

If the value is 1, this means /VSAN/DOMPauseAllCCPs is enabled and the objects owned by this host will be unavailable until the setting is reverted to the default value of 0 by running the following command on the affected hosts.:

[root@esxi#:~] esxcfg-advcfg -s 0 /VSAN/DOMPauseAllCCPs

Additional Information

These articles explain the underlying network mechanics that trigger the DOMPauseAllCCPs failsafe.

KB 435212: vSAN objects showing inaccessible following network outage
Explains how physical network flaps or packet loss (especially to a vSAN Witness) cause the DOM owner to temporarily flag components as inaccessible, triggering internal vSAN safety pauses.

KB 326833: Inaccessible objects in vSAN when all components show as Active
Covers a closely related scenario where objects remain inaccessible after a disruption because the /VSAN/DOMPauseAllCCPs parameter becomes stuck at 1 and must be manually reverted to 0.

These articles cover other common vSAN-layer reasons an ESXi host might fail to enter maintenance mode.

KB 326857 / KB 390478: vSAN host fails to enter maintenance mode (Not enough Upper FD's)
Details the failure that occurs when selecting "Full Data Migration" in a cluster that lacks the extra fault domains required to completely rebuild the data (common in RAID-5/RAID-6 configurations). Recommends using "Ensure Accessibility" instead.

KB 440130: ESXi host fails to enter maintenance mode (Internal vSAN Error)
Addresses a specific known issue in ESXi 8.0 where the /VSAN/DeltaComponent advanced parameter incorrectly toggles to 0. The fix requires manually setting it back to 1.

KB 452297: vSAN host stuck entering maintenance mode (Canceled Decommission)
Explains how a previously canceled or hung maintenance mode task can leave a stale decommission state (decomState: 9) in the CMMDS, requiring a restart of the clomd service to clear.