The reason for adding capacity to your array is generally that the array is getting utilized and usable capacity is getting full. You can view the used capacity of the array by either using the GUI or CLI.
The array will also send warning alerts by default when the used capacity gets to 80%, 90%,95% threshold. For more information Alert 25 - Storage Consumption has Reached X% of Usable Capacity
► Using GUI
Capacity can be checked on the main Dashboard when you log in to the array.
Using CLI
purearray list --space
Output Example:
pureuser@cbsavspv2> purearray list --space
Name Capacity Parity Provisioned Size Thin Provisioning Data Reduction Total Reduction Unique Snapshots Shared System Replication Total
cbsavspv2 4.65T 100% 31395911M 97% 3.9 to 1 >100 to 1 24.85G 160.30G 84.19G 0.00 0.00 269.34G