ESXi upgrade using online depot fails with “Unable to allocate output buffer”

Products

• VMware vSphere ESXi

Issue/Introduction

When attempting to list or install software profiles from an online depot, such as:

esxcli software sources vib get --depot=https://dl.broadcom.com/<token-ID>/path_to_repository
esxcli software sources profile list --depot=https://dl.broadcom.com/<token-ID>/path_to_repository

Receive one or more of the following errors:

[MetadataIOError]
Failed to read configSchemas/...json: Unable to allocate output buffer.

[MemoryError]
Please refer to the log file for more details.

In the /var/log/vmkernel.log:

Admission failure in path: host/vim/vmvisor/esximage/python.#####
uw.##### requires #### KB, asked #### KB from python.##### which has ### KB occupied and 0 KB available.

Cause

ESXi cannot allocate additional memory to the esxcli process. As a result, the kernel denies the request, leading to “Admission failure” or “Unable to allocate output buffer” errors.

Resolution

Option 1: Free up process memory before retrying

• Put the Host in the maintenance mode to release the process memory Place a Host in Maintenance Mode
• Run the esxcli software sources profile list --depot=https://dl.broadcom.com/<token-ID>/path_to_repository
• And then esxcli software sources profile update --depot=https://dl.broadcom.com/<token-ID>/path_to_repository --profile=<ESXi profile from above step> 

Option 2: Use offline bundle 

• Download the offline zip bundle for the desired version from the Broadcom Support Portal
• Upload the file to a datastore accessible by the host.
• Then refer to the following kb to upgrade to the desired version: Upgrade a Host with Offline Zip Bundle

If both options does not work, consider rebooting the ESXi Rebooting an ESXi Server host and then retry.

Option 3: Use the Lifecycle Manager

vLCM can be used to configure the Depots and then remediate the ESXi Host(s) Working With the vSphere Lifecycle Manager Depot