VMFS Datastore Not Visible on 32 GB Boot Drive After ESXi 8.0 U3 Installation or Upgradation

Products

• VMware vCenter Server

Issue/Introduction

A VMFS datastore is not visible or automatically created on the 32 GB boot drive after installing or upgrading to ESXi 8.0 U3.

Environment

VMware vSphere ESXi 8.x

Cause

Starting with ESXi 7.0 and extending into ESXi 8.0, the system storage partition layout was redesigned. A 32 GB boot drive is smaller than the 128 GB capacity threshold required for automatic VMFS datastore creation. Consequently, the ESXi installer allocates 100% of the available remaining space to the ESX-OSData partition.

The ESX-OSData partition consolidates legacy scratch partitions, VMware Tools lockers, and core dumps into a single volume to meet modern data retention and logging requirements. Because the boot drive is 32 GB, the system reserves the entirety of the usable space for host operations and stability, leaving no capacity to automatically provision a local VMFS-L datastore.

Resolution

1. Provision additional storage capacity to host virtual machines or ISO images.
2. Add separate local disks (SSD, NVMe, HDD) to the ESXi host or map external shared storage (iSCSI, NFS, Fibre Channel).
3. Format these new devices as VMFS datastores.
4. Do not attempt to manually shrink the ESX-OSData partition. Manual alteration of the persistent storage layout on a 32 GB drive is unsupported and will cause severe host instability (a minimum of 32 GB is required for ESXi 8.0 persistent storage).

Additional Information

For detailed requirements regarding the system storage layout and the specific conditions for automatic VMFS datastore creation (which requires a high-endurance medium larger than 128 GB), refer to the ESXi System Storage Overview.