Virtual machine crashed during backup

Products

• VMware vSphere ESXi

Issue/Introduction

• Virtual machine crashed when backing up with third-party software with below error message in its vmware.log:

<YYYY-MM-DD>T<time>Z[+0.000] Cr(01) filtPoll - PANIC: Unexpected signal: 6.
<YYYY-MM-DD>T<time>Z[+0.000] In(05) filtPoll - Panic: can't get userlevel lock.
<YYYY-MM-DD>T<time>Z[+0.796] Wa(03) filtPoll - A core file is available in "/vmfs/volumes/<vm-path>/vmx-zdump.000"
  
  
• In vmware.log of the virtual machine before the crashed, there is third-party IO filter loaded:
  
  <YYYY-MM-DD>T<time>Z In(05) vcpu-0 - PluginLdr_Load: Loaded plugin 'libvmiof-disk-veecdp.so' from '/usr/lib64/vmware/plugin/libvmiof-disk-veecdp.so'
  
  
• In vmkernel.log of the ESXi host, there are messages that indicate the virtual machine crashed on IO Filter:
  
  <YYYY-MM-DD>T<time>Z cpu54:14223116)UserDump: 2823: vmx-filtPoll:<vm-name>: Userworld(vmx-filtPoll:<vm-name>) coredump complete.

Environment

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

Resolution

The virtual machine crashed on the third-party IO Filter. In this case, it is Veeam veecdp. Contact the backup vendor to further check the issue.