vSphere: How to Decrypt Encrypted Zdump Files After a PSOD and Create Support Bundle

Decrypt Core Dump Files and Create Support Bundle

Prerequisites

• SSH access to the ESXi host that experienced the PSOD.
• vSphere version 7.x or later.

Procedure

• Connect to the affected ESXi host via SSH.
• Check whether each core dump in /var/core is encrypted.
• If encrypted, decrypt the core dump file.
• Create a new support bundle.
• Upload the support bundle directly to the case for analysis 

Step‑by‑Step Commands

# SSH to the ESXi host
$ ssh root@[ESXI_HOST_IP]

# Verify encryption status of the first core dump
crypto-util envelope describe --offset 4096 /var/core/vmkernel-zdump.1

# Decrypt the first core dump if it is encrypted
crypto-util envelope extract --offset 4096 /var/core/vmkernel-zdump.1 /var/core/unenc-vmkernel-zdump.1

# Decrypt additional core dump files (repeat for each .zdump file)
crypto-util envelope extract --offset 4096 /var/core/vmkernel-zdump.2 /var/core/unenc-vmkernel-zdump.2

# Create a new support bundle
vm-support
vm-support -w use the -w to specify loaction example: ( vm-support -w /vmfs/volume/DATASTORE_NAME )

# The default bundle location is:
/var/tmp/ /var/log/ depending on which loacation has the most space