What is the HOSTD and VPXA

 

HOSTD 

The vmware-hostd management service is the main communication channel between ESX/ESXi hosts and VMkernel. If vmware-hostd fails, ESX/ESXi hosts disconnects from vCenter Server/VirtualCenter and cannot be managed, even if you try to connect to the ESX/ESXi host directly. It knows about all the VMs that are registered on that host, the luns/vmfs volumes visible by the host, what the VMs are doing, etc. Most all commands or operations come down from VC through it. i.e, powering on a VM, VM vMotion, VM creation, etc. 

Restart the management agent 

/etc/init.d/hostd restart 

vpxa acts as an intermediary between the vpxd process on vCenter Server and the hostd process to relay the tasks to be performed on the host. 

 The vpxa process is started on the ESXi host when it is added to the vCenter Server inventory. vpxa communicates with the ESXi host agent named hostd. The hostd process runs on the ESXi host and it is used for managing most of the operations on the host. Most commands come from vCenter Server through hostd (e.g. virtual machine creation, migration, removal, etc…). 

 

 ESXi Log Files 

/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. 

My preferred way, when possible, is to SSH to the host and view the log files from the SSH console. Once connected you can view logs in a variety of ways such as: 

cat hostd.log | more 

less hostd.log 

tail hostd.log 

tail -f hostd.log 

zcat /var/log/boot.gz 

# grep -i failed /var/log/vmkernel.log | less 

You can also search logs using grep: 

cat hostd.log | grep keyword 

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