The system supports several ways to monitor physical capacity usage to ensure that storage is sufficient for host workloads.
The Capacity section on the Dashboard provides an overall view of system capacity through physical capacity, volume capacity, and capacity savings. The capacity displays as actual capacity and also as a percentage of the total capacity. Dashboard provides the system-level reporting for capacity usage.
Physical capacity indicates the total capacity in all storage on the system. Physical capacity includes all the storage the system can virtualize and assign to pools. Physical capacity is displayed in a bar graph and divided into three categories: Stored Capacity, Available Capacity, and Total Physical. Stored Capacity indicates the amount of capacity that is being used on the system after compression, deduplication, and thin-provisioning savings. This value does include the capacity that is used by metadata for deduplicated and compressed volumes. Stored Capacity indicates the amount of capacity that is being used on the system after capacity savings. The system calculates the stored capacity by subtracting the available capacity and any reclaimable capacity from the total capacity that is allocated to MDisks. To calculate the percentage, the stored capacity is divided by the total capacity that is allocated to MDisks. On the left side of the bar graph, the stored capacity is displayed in both the total capacity and as a percentage. The total Available Capacity displays on the right side of the bar graph. Available capacity is calculated by adding the free capacity and the total reclaimable capacity. To calculate the percentage of available capacity on the system, the available capacity is divided by the total amount of capacity that is allocated to MDisks. The Total Physical capacity displays on the right under the bar graph and shows all the physical capacity available on the system. The bar graph is a visual representation of capacity usage and availability and can be used to determine whether more storage needs to be added to the system. Select View MDisks to view more information about the physical capacity of the system on the MDisks by Pools page.
The system supports both data reduction pools and standard pools. In the management GUI, select to view all the pools configured on the system. Data reduction pools are shown with Data Reduction set to Yes. In the management GUI, reclaimable capacity is added to the available capacity for the data reduction pool. Reclaimable capacity is unused capacity that is created when data is overwritten, volumes are deleted, or when data is marked as unneeded by a host by using the SCSI unmap command. In data reduction pools, reclaimable capacity is monitored and collected and eventually redistributed back to the pool for use. For standard pools, available capacity does not include any reclaimable capacity. In the command line interface, lsmdiskgrp command displays the different values that apply to data reduction and standard pools. For data reduction pools, the value for reclaimable_capacity indicates the amount of unused capacity that is available after data is reduced in the pool. Unlike with the management GUI, reclaimable_capacity is not included in the free_capacity value that is displayed in the lsmdiskgrp.
If external storage systems are shared across several pools, analyzing MDisk capacity usage can be easier to determine whether more capacity is needed. If capacity from storage system is shared across different pools, then provisioning groups are created. Provisioning groups are objects that identify whether storage is shared across multiple pools. The MDisks by Pools page in the management GUI, displays all pools and their assigned MDisk. If you are not sure whether external storage systems are shared across several pools, right-click the pool and select View Resources to display the provisioning group that is associated with the pool.
If your system configuration dedicates specific storage systems to individual pools, analyzing the pool capacity usage can determine whether more capacity is needed. On the Pools page, check each MDisk in the pool for capacity and use the value for Storage System - LUN to determine the external storage system that provides the MDisk with space.