Unicode Decoder Error : Invalid Start Byte when trying to install VMWare ESXI 8.0.3

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms

• When attempting to install or upgrade VMware ESXi 8.0.3 using the VMware-ESXi-8.0U3-24022510-depot.zip file, the installation fails, and the following error is observed: Unicode Decoder Error: Invalid Start Byte

• Additionally, when trying to upgrade using the command line (esxcli software profile update), the following error occurs:

esxcli software profile update -d /vmfs/volumes/5f911c87-33d79e6e-d9f0-b88303530ad6/ISO/VMware-ESXi-8.0U3-24022510-depot.zip -p ESXi-8.0U3-24022510-standard
 [HardwareError]
 Hardware precheck of profile ESXi-8.0U3-24022510-standard failed with errors: <VFAT_CORRUPTION ERROR: A problem with one or more vFAT bootbank partitions was detected. Please refer to KB 91136 and run dosfsck on bootbank partitions.>
 Please refer to the log file for more details.

• The /var/log/vobd.log file shows the following entries related to the error:

2025-03-24T06:41:21.758Z: [GenericCorrelator] 47008208us: [vob.user.scratch.partition.size.small] Size of scratch partition 62319b17-6285de8c-c2d3-20677c1c41f0 is too small. Recommended scratch partition size is 17714 MiB.
2025-03-24T06:41:21.758Z: [UserLevelCorrelator] 47008208us: [vob.user.scratch.partition.size.small] Size of scratch partition 62319b17-6285de8c-c2d3-20677c1c41f0 is too small. Recommended scratch partition size is 17714 MiB.
2025-03-24T06:41:21.758Z: [UserLevelCorrelator] 47008385us: [esx.problem.scratch.partition.size.small] Size of scratch partition 62319b17-6285de8c-c2d3-20677c1c41f0 is too small. Recommended scratch partition size is 17714 MiB.

• Scratch partition is on OSDATA of ESXi

Environment

VMware ESXi 8.0

Cause

• Upgrade Failure: The upgrade failed due to the unavailability of the persistent scratch location.
• Missing VIB Dependencies: The selected baseline for the upgrade has VIBs (vSphere Installation Bundles) that are missing dependencies, which caused the upgrade to fail.

• When remediated giving below error:

Software or system configuration of host <Host Name> is incompatible. Check scan results for details.

/scratch Partition on SD/USB:

• The ESXi installer does not create the /scratch partition on an SD card or USB drive by default.

• It tries to find persistent storage and create the /scratch partition there.

• If no supported persistent storage is available, a 250 MB /tmp partition is created on a ramDisk instead.

• This ramDisk partition could limit the performance of the ESXi host if it runs out of space.

• VMware does not support creating the /scratch partition on SD or USB boot media.

VIB Dependency Issue:

• The missing dependencies in the selected upgrade baseline are preventing the installation from completing successfully.

• This issue could be blocking the upgrade due to incompatible or missing VIBs that are essential for the upgrade process.

Resolution

Configure /scratch Partition on Persistent Storage:

• The /scratch partition must be configured on persistent storage (e.g., a local HDD/SSD or a boot-from-SAN device) to ensure proper functionality during upgrades and operations.

• VMware does not support using SD or USB boot media for the /scratch partition.

• For more details, refer to the KB article on Creating a persistent scratch location for ESXi 8.x/7.x/6.x

Remove VIBs with Missing Dependencies:

• Identify and remove the VIBs that are missing dependencies from the upgrade baseline.

• Ensure the VIBs in the baseline are compatible with the current environment.

Upgrade the ESXi Host:

• Once the persistent scratch location is properly configured and VIB dependencies are addressed, proceed with the ESXi upgrade.

• The upgrade should complete successfully once these steps are followed.