vSAN hard disk health status show as Evacuated or Evacuating

Products

• VMware vSAN

Issue/Introduction

 

Symptoms:

• vSAN disk may show the status as 'Evacuated' / 'Evacuating' in disk management for a vSAN host.

  
  
  
  

• /var/run/log/vobd.log reports the disk to be unhealthy:
  
  YYYY-MM-DDTHH:MM:SS.638Z In(14) vobd[2097860]:  [vSANCorrelator] 3558537147848us: [vob.vsan.lsom.diskunhealthy] vSAN device #######-####-####-####-############ is unhealthy.
YYYY-MM-DDTHH:MM:SS.638Z In(14) vobd[2097860]:  [vSANCorrelator] 3558664771456us: [esx.problem.vob.vsan.lsom.diskunhealthy] vSAN device #######-####-####-####-############ is unhealthy.

Environment

VMware ESXi 7.x

VMware ESXi 8.x

Cause

Disk/disk group gets evacuated due to impending failure on disk. When vSAN detects an impending capacity disk failure (known as Dying Disk Handling or DDH), it automatically begins to proactively evacuate the data from the affected disk/disk groups to healthy disks/disk groups in the cluster. This process is designed to prevent data loss and maintain accessibility.

• Entire Disk Group Evacuation:
  • This occurs if the impending failure is reported for the Cache disk in a vSAN Hybrid or vSAN All-Flash cluster.
  • This also occurs if the impending failure is reported for any capacity disk int that disk group in an All-Flash cluster where de-duplication is enabled.
    
    
• Affected Capacity Disk Evacuation:
  • This occurs if the impending failure is reported for a capacity disk in a vSAN Hybrid Cluster or All-Flash cluster without de-duplication.

The health of the disk can be validated using the below command:

[Host-01:~] esxcli storage core device smart get -d naa.################
Parameter                    Value                Threshold    Worst    Raw
--------------------------------------------    -------------------------------     ------------------    -----------    ------
Health Status                IMPENDING FAILURE    N/A          N/A      N/A
Media Wearout Indicator      86                   100          N/A      N/A
Write Error Count            0                    N/A          N/A      N/A
Head Error Count             916                  N/A          N/A      N/A
Power Cycle Count            0                    N/A          N/A      N/A
Reallocated Sector Count     0                    N/A          N/A      N/A
Drive Temperature            29                   N/A          N/A      N/A
Write Sectors TOT Count      1070746404638        N/A          N/A      N/A
Head Sectors TOT Count       2717017976057        N/A          N/A      N/A
Program Fail Count           247                  N/A          N/A      N/A
Erase Fail Count             0                    N/A          N/A      N/A

From the /var/run/log/vobd logs, the disk is reporting impending failure and suggest to replace the disk.

2025-11-20T06:30:43.256Z In(14) vobd[2098051]: [vSANCorrelator] 3141556237us: [vob.vsan.lsom.devicewithsmartfailure] vSAN device naa.################ smart health status is impending failure. It will be evacuated and unmounted, consider replacing it.
2025-11-20T06:30:43.256Z In(14) vobd[2098051]: [vSANCorrelator] 3742867710us: [eax.problem.vob.vsan.lsom.devicewithsmartfailure] vSAN device naa.################ smart health status is impending failure. It will be evacuated and unmounted, consider replacing it.
2025-11-20T06:30:43.262Z In(14) vobd[2098051]: [vSANCorrelator] 3141561996us: [vob.vsan.lsom.diskunhealthy] vSAN device ########-####-####-####-############ is unhealthy.
2025-11-20T06:30:43.262Z In(14) vobd[2098051]: [vSANCorrelator] 3141657213us: [esx.problem.vob.vsan.lsom.diskunhealthy] vSAN device ########-####-####-####-############ is unhealthy.

Resolution

1. Place the host in maintenance mode with ensure accessibility.
   
   
2. Delete affected/unhealthy disk group (after disk group evacuation completes).
   
   
3. Contact the hardware vendor to replace faulty cache disk 
   
   
4. Recreate the disk group post replacement of cache disk.