The df Command

Used for checking disk space usage on the ESX/ESXi service console partitions

This objective on the VCAP-DCA exam is slightly ambiguous but I have decided to focus on the command “df” which stands for disk filesystemor disk free. This command is used to display the filesystems that are mounted to that particular host and the usage associated with these filesystems

The “-h” switch makes the output human readable

Instructions

• Log into an SSH session or vMA or locally whichever you prefer
• Type df-h to view an easily readable format

• Review the Use% for each of the listed items. If any of the volumes listed are 100% full, they must be investigated to determine if space can be freed. The most important mount points to investigate on a default installation of ESX are the / and /var/log mounts because if they are full they can prevent proper operation of the ESX host
• VisorFS is a Special-purpose File System for Efficient Handling of System Images
• The vfat partition is created for new installations of ESXi, during the autoconfiguration phase. In vSphere 5 it is now a 4GB vfat scratch partition

The vdf Command

Checking disk space usage on a VMFS volume of an ESX/ESXi host

• Log into an SSH session or vMA or locally whichever you prefer
• Type vdf-h to view an easily readable format

•  Review the Use% for each of the listed items. If any of the volumes listed are 100% full, they must be investigated to determine if space can be freed. If a VMFS volume is full you cannot create any new virtual machines and any virtual machines that are using snapshots may fail

Useful VMware KB Article

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1003564