Working with ESXi Core Dumps

Collecting core dumps gives VMware support (and massochists) something to evaluate in the event of an ESXi PSOD. Collecting and viewing ESXi core dumps involves serveral elements- ESXi configuration, collector configuration and a dump viewer.

Collector Configuration

Fortunately, the VMware vCenter Server Appliance can be used to collect crash dumps. Unfortunately, the service can only be configured on the long deprecated Flash client.

Log into the Flash client at

Head to Home > Administration > System Configuration > Services > VMware vSphere ESXi Dump Collector ( > Actions > Edit Startup Type > Automatic

SSH to the vCSA

Start the dump collector, verify it has started and enter a shell promt

service-control --start vmware-netdumper
service-control --status vmware-netdumper

To customize dump collector service configuration

vi /etc/sysconfig/netdumper

Apply changes

service-control --restart vmware-netdumper

ESXi Configuration

SSH to an ESXi host

esxcli system coredump network set --interface-name vmk0 --server-ipv4 --server-port 6500
esxcli system coredump network set --enable true

where `vmk0` is the outgoing interface and `–server-ipv4 address` is core dump server

Viewing Dumps

Following crash, copy crash dump from vCSA to any ESXi host-

Enable SSH on target ESXi host

From the collector, copy dump from collector to an ESXi host

scp /var/core/netdumps/ffff/10/0/0/20/zdump_ffff. [email protected]:/vmfs/volumes/lun001

From the ESXi host, extract the dump file

esxcfg-dumppart -L /vmfs/volumes/lun001/zdump_ffff.

Open the dump file

tail -n 250 vmkernel-log.1

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