Config vVols

When a VMware administrator creates a vVol-based VM, vCenter creates a 4-gigabyte thin-provisioned configuration vVol (config vVol) on the array, which ESXi formats with VMFS. A VM’s config vVol stores the files required to build and manage it: its VMX file, logs, VMDK pointers, etc. To create a vVol-based VM, right-click any inventory pane object to launch the New Virtual Machine wizard and specify that the VM’s home directory be created on a vVol datastore.

When VM creation is complete, a directory with the name of the VM appears in the array’s vVol datastore. The directory contains the VM’s vmx file, log file and an initially empty vmsd file used to store snapshot information.

In the Web Client, a vVol datastore appears as a collection of folders, each representing a mount point for the mini-file system on a config vVol. The Web Client GUI Browse Datastore function and ESXi console cd operations work as they do with conventional VMs. Rather than traversing one file system, however, they transparently traverse the file systems hosted on all of the array’s config vVols.

A FlashArray creates a config vVol for each vVol-based VM. Arrays name config vVols by concatenating the volume group name with config-<UUID>. Arrays generate UUIDs randomly; an array administrator can change them if desired.

An array administrator can search for volumes containing a vVol-based VM name to verify that its volume group and config vVol have been created.

As objects are added to a vVol-based VM, VMware creates pointer files in its config vVol; these are visible in its directory. When a VM is deleted, moved to another array, or moved to a non-vVol datastore, VMware deletes its config vVol.