Host down with PSOD with a backtrace UnmapManager

Products

• VMware vSphere ESXi

Issue/Introduction

In the core dump you will see backtrace similar to this:

cpu34:2098460)Backtrace for current CPU #34, worldID=2098460, fp=0x4317ee0a56f8
cpu34:2098460)0x4539e3f1bec0:[0x42000e658e18]UnmapManager@esx#nover+0x5ac stack: 0x4317ebc5e188, 0x4317ee0a5710, 0xc7a900000, 0x61935, 0x0
cpu34:2098460)0x4539e3f1bfe0:[0x42000d6dde22]CpuSched_StartWorld@vmkernel#nover+0xbf stack: 0x0, 0x42000d145570, 0x0, 0x0, 0x0
cpu34:2098460)0x4539e3f1c000:[0x42000d14556f]Debug_IsInitialized@vmkernel#nover+0xc stack: 0x0, 0x0, 0x0, 0x0, 0x0
cpu34:2098460)VMware ESXi 8.0.3 [Releasebuild-25205845 x86_64]

Environment

ESXi 8.0

Cause

This issue is caused due to a bug in the ESXi software due to a unmap feature. It is seen only when the unmap feature is enabled. It is caused by a race condition and is extremely rare to occur during regular workflow.

Resolution

Broadcom is working on coming up with a fix for this issue. There is no known solution at this point.