The Space Utilization By File Type chart displays datastore space usage for virtual disks, swap files, snapshot files, and other virtual machine files.

Note: This chart does not show historical statistics. It only shows the most recently available data, which may be up to 30 minutes late, depending on when the last statistics rollup occurred. In addition, statistics are not collected across all datastores at one time. They are collected asynchronously.

The Space Utilization by File Type chart is located in the Storage view of the data center Performance tab.

Datastore Counters

Table 1. Data Counters
File Type Description
Virtual Disks

Amount of disk space used by virtual disk files.

Virtual disk files store the contents of the virtual machine's hard disk drive. It includes information that you write to a virtual machine's hard disk, such as the operating system, program files, and data files. The files have the extension .vmdk and appear as a physical disk drive to a guest operating system.

Note: Delta disks, which also have an extension .vmdk, are not included in this file type.
  • Counter: used
  • Stats Type: Absolute
  • Unit: Gigabytes (GB)
  • Rollup Type: Latest
  • Collection Level: 1 (4)
Swap Files

Amount of disk space used by swap files.

Swap files back up the virtual machine's physical memory.

  • Counter: used
  • Stats Type: Absolute
  • Unit: Gigabytes (GB)
  • Rollup Type: Latest
  • Collection Level: 1 (4)
Snapshots

Amount of disk space used by virtual machine snapshot files.

Snapshot files store information about virtual machine snapshots. They include snapshot state files and delta disk files. A snapshot state file stores the running state of the virtual machine at the time of the snapshot. It has the extension .vmsn. A delta disk file stores the updates made by the virtual machine to the virtual disks after a snapshot is taken.

  • Counter: used
  • Stats Type: Absolute
  • Unit: Gigabytes (GB)
  • Rollup Type: Latest
  • Collection Level: 1 (4)
Other VM Files

Amount of disk space used by all other virtual machine files, such as configuration files and log files.

  • Counter: used
  • Stats Type: Absolute
  • Unit: Gigabytes (GB)
  • Rollup Type: Latest
  • Collection Level: 1 (4)
Other Amount of disk space used by all other non-virtual machine files, such as documentation files and backup files.
Free Space Amount of disk space not currently in use.
Total Space

Amount of disk space available to the datastore. It defines the datastore capacity. The chart displays the information for datastores but not for data centers.

total space = virtual disk space + swap file space + snapshot space + other VM file space + other space + free space

Chart Analysis

The datastore is at full capacity when the used space is equal to the capacity. Allocated space can be larger than datastore capacity, for example, when you have snapshots and thin-provisioned disks. If possible, you can provision more space to the datastore, or you can add disks to the datastore or use shared datastores.

If snapshot files are consuming high datastore space, consider consolidating them to the virtual disk when they are no longer needed. Consolidating the snapshots deletes the redo log files and removes the snapshots from the vSphere Client user interface. For information about consolidating the data center, see the vSphere documentation.