When attempting to take a snapshot with vSAN Data Protection you will get an error in vCenter stating
"Take snapshot task failed. Check the vSAN data protection UI logs for details."
vSAN 8.0+
Review of the vSAN Snapshot service appliance or data protection appliance logs you will see the following
In /var/log/vmware/snapservice/snap-service-ui.log
{"level":"error","timestamp":"2025-##-##T##:##:##.###Z","C":"controller/LogsImpl.go:48","message":"[\"[vSAN SM ERROR]: \",\"Take snapshot task failed. Check the vSAN data protection UI logs for details.\"]","error":"UI error"........
In /var/log/vmware/snapservice/snapservice.log
{"level":"info","timestamp":"2025-##-##T##:##:##.###Z","C":"snapshots/prechecks.go:56","message":"cluster Health is RED","opID":"########","cluster":"domain-c######"}
Review the vSAN cluster health by going to go to the Cluster > Monitor > vSAN > Skyline Health
(screen shots are based off newer versions of vCenter and ESXi)
Once in the health check you can review the unhealthy results and get more details as well as directions on addressing the issue by selecting the troubleshooting button under each health check.
Review the additional Information section of this KB for more information on some of the health checks and how to address them.
Once all alarms are addressed the Data Protection health check will pass and allow snapshots to be taken.
Following a selection of available KB Articles related to the vSAN Healthcheck:
vSAN Health Check Information
vSAN Health Service - Cluster Health - Advanced vSAN configuration in sync
vSAN Health Service - Cluster Health - vSAN daemon liveness check
vSAN Health Service - Limits Health - Current Cluster Situation
vSAN Health Service - Limits Health - After one additional host failure
vSAN Health Service - vSAN HCL Health - Controller is VMware certified for ESXi release
vSAN Health Service - vSAN HCL Health - Controller Driver
vSAN Health Service - vSAN HCL Health - vSAN HCL DB up-to-date
vSAN Health Service - vSAN HCL Health - SCSI Controller on vSAN HCL
vSAN Health Service - Physical Disk Health - Overall Disk Health
vSAN Health Service - Physical Disk Health - Disk Capacity
vSAN Health Service - Physical Disk Health - Component Metadata Health
vSAN Health Service - Physical Disk Health - Congestion
vSAN Health Service - Physical Disk Health - Memory pools
vSAN Health Service - Network Health - Hosts disconnected from vCenter Server
vSAN Health Service - Network Health - Unexpected vSAN cluster members
vSAN Health Service - Network Health - vSAN Cluster Partition
vSAN Health Service - Network Health - Hosts with vSAN disabled
vSAN Health Service - Network Health - All hosts have a vSAN vmknic configured
vSAN Health Service - Network Health - Hosts small ping test (connectivity check) and Hosts large ping test (MTU check)
vSAN Health Service - Network Health - Hosts with connectivity issues