Extracting the log file after an ESX or ESXi host fails with a purple screen error

To
resolve this issue, extract the log file from a vmkernel-zdump file using a command
line utility on the ESX or ESXi host. This utility differs for different
versions of ESX or ESXi.

For ESX 3.x use
the vmkdump utility:

#
vmkdump -l vmkernel-zdump-filename


For ESXi 3.5,
ESXi/ESX 4.x and ESXi 5.x, use the esxcfg-dumppart utility:

#
esxcfg-dumppart -L