Brief about ESXi Log Files and Locations.

Working with ESX(i) log files is important when troubleshooting issues within the virtual environment. So sharing few important log files of ESXI as follows.

• /var/log/auth.log: ESXi Shell authentication success and failure attempts.
• /var/log/dhclient.log: DHCP client log.
• /var/log/esxupdate.log: ESXi patch and update installation logs.
• /var/log/hostd.log: Host management service logs, including virtual machine and host Task and Events, communication with the vSphere Client and vCenter Server vpxa agent, and SDK connections.
• /var/log/shell.log: ESXi Shell usage logs, including enable/disable and every command entered.
• /var/log/boot.gz: A compressed file that contains boot log information and can be read using zcat /var/log/boot.gz|more.
• /var/log/syslog.log: Management service initialization, watchdogs, scheduled tasks and DCUI use.
• /var/log/usb.log: USB device arbitration events, such as discovery and pass-through to virtual machines.
• /var/log/vob.log: VMkernel Observation events, similar to vob.component.event.
• /var/log/vmkernel.log: Core VMkernel logs, including device discovery, storage and networking device and driver events, and virtual machine startup.
• /var/log/vmkwarning.log: A summary of Warning and Alert log messages excerpted from the VMkernel logs.

/var/log/vmksummary.log: A summary of ESXi host startup and shutdown, and an hourly heartbeat with uptime, number of virtual machines running, and service resource consumption.