Description of Virtual Volume pie chart components in vCenter
Article ID: 397954
Updated On:
Products
Issue/Introduction
A vVol datastore is a logical storage pool managed and maintained by the array. This datastore can be dynamically extended or shrinked on the array, similarly the capacity usage is also managed and maintained by the array. vSphere queries this data through VAAI and displays it on the vCenter UI.
A pie chart for a Virtual Volume datastore displays storage metrics for a single or multiple virtual machine objects, based on the file types and the amount of space allocated by them.
Environment
VMware ESXi
VMware vCenter Server
Resolution
Virtual Disks - Consists of Data-vVols. A data virtual volume that corresponds directly to each virtual disk .vmdk file. As virtual disk files on traditional datastores, virtual volumes are presented to virtual machines as SCSI or NVMe disks. Data-vVol can be either thick or thin-provisioned.
Other VM Files - This is the space occupied by the files stored in the VM home folder (Config-vVol), i.e. the VMX logs, statistics, ancillary VM files etc.
Snapshots - Consists of snapshot-vVols. A virtual memory volume to hold the contents of virtual machine memory for a snapshot (Thick-provisioned). vSphere snapshots are also included in this segment of the pie chart but it does not include independent snapshots of volumes taken on the array.
Swapfiles - Consists of Swap-vVol. Created when a VM is first powered on. It is a virtual volume to hold copies of VM memory pages that cannot be retained in memory. Its size is determined by the VMs memory size. It is thick-provisioned by default.
Other - This segment consists of the files and data which is not being tracked by vSphere. Example: unregistered VMs, detached virtual disks, array snapshots etc.
This is typically computed as: Consumed Space reported by array - Space consumed by files tracked by vSphere i.e. VM virtual disk, swap, vSphere snapshots etc.
Free Space - This is the free space on the vVol datastore
Total Space - This is total capacity reported by the array
What is a Config-vVol ?
A configuration vVol maps directly to the "VM home folder".
Config-vVol is a thin provisioned LUN or volume on the storage array. Since it is thin provisioned it should not occupy any space unless vSphere writes to it.
Config-vVol is formatted with a filesystem and is used as VM home folder, whenever a file is created inside the VM home folder, vSphere writes to the config-vVol.
This means that space occupied by "Other VM files" is approximately equal to the space consumed by the config-vVol on the datastore. There is a delta where the filesystem metadata itself will consume some space, but it should be minimal.
Additional Information
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