Q:
What does the space reporting feature do?A: vSAN space reporting is enabled by default in vSAN 6.2 and later releases.
Using the vSAN space, you can view this information:
- General vSAN space usage.
- Detailed space usage breakdown that indicates the total amount of used and free space that is available.
- The purpose for which the space is used.
Q: What is the meaning of each reported data value shown in the space reporting view?A: The space reporting page includes three portals:
- Capacity overview portal
- Capacity breakdown portal
- Deduplication and compression overview ports
The space usage data definition in the capacity overview portal are listed here.
Capacity Overview
- Provisioning: Logical capacity configured for all objects on the cluster
- Used - Physically Written: Capacity storing actual data of the objects on the vSAN datastore
- Used - VM Over-reserved: Space wasted due to higher than needed space reservation setting. Reducing the object space reservation policy can free up space without the need to delete or move any data
- Used - Total: Space not available for new allocations
- Used - vSAN system overhead: Capacity consumed by vSAN for system needs.
Used Capacity Breakdown
There are two types of capacity breakdown, object types and data types.
Object type breakdown
- Virtual disks: The total space used for all of the virtual disks
- VM home objects: The total space used for the VM home directory
- Performance management object: The total space used for the vSAN performance service
- Vmem: The total space used for the virtual memory for all VMs
- File system overhead: The vSAN file system overhead
- Checksum overhead: The space required for checksum metadata overhead
- The deduplication and compression overhead: The metadata overhead required for deduplication and compression
- The snapshot memory: The total space used for the snapshot memory
- Other: Any other used space such as the user-created file or the VM template in the vSAN datastore
Data type breakdown
- Primary VM data: The total space used for primary VM data. This is user used data in VM/VMDK
- vSAN overhead: The total of all kinds of vSAN overhead including replica, witness, RAID 5/6 component, and so on
- The temporary overhead: The space used when moving objects
Deduplication and compression overview
- Used space before: The total used space before enabling deduplication and compression
- Used space after: The total used space after enabling deduplication and compression
- Saving: The total space savings achieved by enabling deduplication and compression