"The pending transaction requires xxx MB free space" error when installing VIBs on ESXi host - VMware vSphere ESXi

Products

• VMware vSphere ESXi

Issue/Introduction

• Installing VIBs on the ESXi host  fails with the below error:
  
  [root@ESXi### :~ ] esxcli software vib install -v /vmfs/volumes/<Datastore UUID>/NVD_bootbank_NVD-VMware_ESXi 8.0.0 Driver 580.95.02-10EM.800.1.0.20613240.vib
[InstallatiomError]The pending transaction requires ### MB free space, however the maximum supported size is ### MB.Please refer to the log file for more details.

• In the /var/log/esxupdate.log file on the affected ESXi host, similar entries are observed:
  
  vmware.esximage.Errors.InstallationError: The pending transaction requires ### MB free space, however the maximum supported size is ### MB.
  
  Note: The preceding log excerpts are only examples. Date, time, and environmental variables may vary depending on your environment.

Environment

• VMware vSphere ESXi 7.x
• VMware vSphere ESXi 8.x

Cause

• This issue occurs when the bootbank runs out of space on the ESXi host.
• Certain third-party custom images are relatively large. Additionally, extra VIBs are automatically installed depending on the services active in your environment. Consequently, if the combined size of the base image and these additional VIBs exceeds the bootbank's maximum capacity, the VIB installation will fail.
• The bootbank partition lacks sufficient contiguous space to stage the VIB. On legacy installations or upgrades from older versions, bootbanks are limited to ~500 MB (489 MB usable). Modern VIBs may require more than 500 MB for a single transaction.

Resolution

1. Reclaim Bootbank Space via VIB Removal
   

   Free additional space on the bootbank by uninstalling unused VIBs.

   1. 1. Identify Unused VIBs: Run the following command to list and identify third-party VIBs that are currently not in use:
         
         esxcli software vib list
         
         
      2. Enter Maintenance Mode: Place the target ESXi host into Maintenance Mode.
      3. Remove VIBs: Execute the following command to remove the identified unused VIBs:
         
         esxcli software vib remove -n <vib-name>

   Note: To ensure safe removal of unused VIBs from the ESXi host, contact the hardware vendor. For more detailed instructions, refer to the official documentation on removing VIBs from a host.

2. Reinstall ESXi on Larger Boot Media

Execute the df -h command to verify the available space on the bootbank.

If the "required free space" in the error message exceeds the size of the available bootbank, space cannot be safely reclaimed through VIB removal. In this scenario, ESXi must be reinstalled on a larger boot drive. This allows the system to provision appropriately sized bootbank partitions automatically.

Boot Media Requirements:

• • • Minimum: Greater than 32 GB

    • Recommended: 128 GB or larger

Refer: Esxi System Storage Overview