ESXi upgrade or installation failure: Host not compatible with the image. The bootbank partition on the host has a capacity of <size>, the image requires <size>

Products

• VMware vSphere ESXi

Issue/Introduction

• ESXi Host upgrade via vSphere Lifecycle Manager fails with an error similar to below:
  
  Host not compatible with the image. The bootbank partition on the host has a capacity of <size>, the image requires <size>. Remove unnecessary components from the image.
  
  
• Attempting to upgrade the ESXi host via CLI as per Patching ESXi host using Command Line fails with error similar:
  
  [InstallationError]
The pending transaction requires #### MB free space, however the maximum supported size is #### MB.
  
  
• The /var/run/log/esxupdate.log on the ESXi host shows entries similar to below:
  
  YYYY-MM-DDThh:mm:ss Db (15) esxupdate [####] : The pending transaction requires ######## bytes free space, the staging area can hold ######## bytes
...
YYYY-MM-DDThh:mm:ss Db (15) esxupdate [####] : vmware.esximage.Errors.InstallationError: The pending transaction requires ### MB free space, however the maximum supported size is ### MB.

Environment

VMware ESXi 7.x , 8.x

Cause

This issue occurs when the ESXi host’s bootbank does not have enough space to accommodate the components that are being installed.

Some ESXi images may include component(s) that are relatively large. This can result in insufficient space in the bootbank when installing or upgrading any component. This is more likely to happen on hosts with small bootbanks like 500MB or so.

Resolution

To work around this issue, there are two approaches. Choose one of the following:

1. Select components from third-party vendors that are smaller.
   
   Some vendors have multiple component (or VIB) versions for a particular ESXi system.  
   You may be able to select one that is smaller in size. Selecting smaller component(s) may be sufficient to complete installation within the existing bootbank.
   
   
2. Enlarge bootbank with full ESXi install rather than upgrade.
   
   If all required components are larger than bootbank size, check the existing bootbank size with command “df -h”.

   If bootbank is 500 MB, you may be able to increase bootbank size by re-installing ESXi on the existing boot device.  
   As long as the boot device is larger than 10 GB and VMFS is not preserved, an ESXi re-install will re-partition the bootbanks larger than 500 MB.  
   
   Re-installing ESXi requires providing host name, password, and network configuration.
   
   Note that re-partitioning the bootbanks is destructive. Backup data from the boot device to another location if required.
   See, How to back up and restore ESXi host configuration
   
   After ESXi re-install, the bootbank should be large enough to install all components.