You can monitor the capacity of the vSAN datastore, analyze usage, and view the capacity breakdown at the cluster level.

The cluster Summary page includes a summary of vSAN capacity. You also can view more detailed information in the Capacity monitor.

Procedure

  1. Navigate to the vSAN cluster.
  2. Click the Monitor tab.
    Option Description
    vSphere Client Under vSAN, click Capacity to view the vSAN capacity information.
    vSphere Web Client
    1. Click vSAN.
    2. Click Capacity to view the vSAN capacity information.

Results

  • The Capacity Overview displays the storage capacity of the vSAN datastore, including total space, used space, free space, reserved space, and the space that is actually written or physically consumed on the vSAN disks. For clusters that have the deduplication and compression enabled, you can view the compression savings and the compression ratio.
  • The Usable capacity analysis enables you to estimate the free space available based on the storage policy that you selected while keeping the deduplication ratio as 1.
  • The Usage breakdown before dedup and compression displays the usage breakdown based on the categories such as VM usage, user objects, and system usage. You can view a graphical representation of the usage categories. Click the graphic to view the different usage categories.

Following are the different usage categories available:

Category Description
VM usage Displays the following:
  • VM home objects - Displays the VM namespace object.
  • Swap objects - Displays the VM swap files.
  • VMDK - Capacity consumed by VMDK objects that reside on the vSAN datastore that can be categorized as primary data and replica usage. Primary data includes the actual user data written into the physical disk which does not include any overhead. Replica usage displays the RAID overhead for the virtual disk.
  • VM memory snapshots - Memory snapshot file for VMs.
  • Block container volumes (attached to a VM) - Capacity consumed by the container objects that are attached to a VM.
User objects Displays iSCSI objects, block container volumes that are not attached to VM, user-created files, ISO files, and VM templates.
System usage Displays the following:
  • Performance management objects - Capacity consumed by objects created for storing performance metrics when you enable the performance service.
  • File system overhead - Overhead that the on-disk file system takes up on the capacity drives.
  • Checksum overhead - Overhead to store all the checksums.
  • Dedup & compression overhead - Overhead to get the benefits of deduplication and compression. This data is visible only if you enable deduplication and compression.
  • Transient space - Temporary space usage in a cluster.

When you enable deduplication and compression, it might take several minutes for capacity updates to be reflected in the Capacity monitor, as disk space is reclaimed and reallocated. For more information about deduplication and compression, see "Using Deduplication and Compression" in Administering VMware vSAN.

You can check the history of capacity usage in the vSAN datastore. Click Capacity History, select a time range, and click Show Results.