Add cluster to workload domain fails - Prepare ESXi Hosts for vSAN Failed

Products

• VMware SDDC Manager

Issue/Introduction

Adding a new cluster with ESXi hosts to the workload domain fails at Subtask - Prepare ESXi Hosts for vSAN Failed

Message: Failed to prepare primary ESXi Host for vSAN
Remediation Message: Please contact support for more details on this error

Search domanmanager.log for VsanDiskValidator , you will find the host FQDNs that point the error configuration for the disks allocated - 

^{yyyy-mm-ddThh:mm:ss ERROR [vcf_dm,68af067eb47f8f0691bc1b96e48227ae,4906] [c.v.e.s.v.v.VsanDiskValidator,dm-exec-16]  Failed to validate vSAN disk availability
com.vmware.evo.sddc.common.core.error.InvalidStateException: ESXi Host hostname_fqdn has 3 different SSD disk sizes, only 2 are allowed
        at com.vmware.evo.sddc.validation.validator.vsan.VsanClusterUtil.processVsanAllFlashWithUndefinedSsdDisks(VsanClusterUtil.java:55)
        at com.vmware.evo.sddc.validation.validator.vsan.VsanConfigFactory.generateValidVsanConfig(VsanConfigFactory.java:57)
        at com.vmware.evo.sddc.validation.validator.VsanDiskValidator.isValid(VsanDiskValidator.java:122)
        at com.vmware.vcf.hostmanager.action.ValidateHostVsanDisksAction.execute(ValidateHostVsanDisksAction.java:66)}

 

 

Environment

VMware Cloud Foundation 5.x

Cause

Unsupported configuration the vSAN disk allocation.

vSAN Disk Allocation in VCF for All flash configuration (SSD or NVMe) supports utmost two different sizes of disks.

Resolution

Mark the third disk offline. 
A workaround for this issue is also documented in KB article - https://knowledge.broadcom.com/external/article/395979 .