During generating support bundle, vdfstool crashed. FSVM might power off and power on automatically in a same time.
From vobd.log, you could confirm that cores of vdfsd-proxy-zdump and vdfsd-server-zdump were generated.
YYYY-MM-DDTmm:hh:ss.###Z: [UserWorldCorrelator] 18390982385783us: [vob.uw.core.dumped.encrypted] /usr/lib/vmware/vdfs/bin/vdfstool(#######) /var/core/vdfsd-proxy-zdump.000
YYYY-MM-DDTmm:hh:ss.###Z: [UserWorldCorrelator] 18390984028179us: [vob.uw.core.dumped.encrypted] /usr/lib/vmware/vdfs/bin/vdfstool(#######) /var/core/vdfsd-server-zdump.000
ESXi 7.0
It's a known issue fixed in 7.0 U3o or later.
Update ESXi to 7.0 U3o or later, since there is no workaround for this issue.