An administrator checks a storage container in Prism Central. Total capacity is 100 TiB, used capacity is 55 TiB, but free capacity reports only 35 TiB. The capacity view also lists 10 TiB as reserved capacity. Why does free capacity not equal total minus used?

Nutanix capacity reporting separates total capacity, used capacity, and free capacity. Free capacity represents usable unallocated space after subtracting both current consumption and capacity set aside for internal operations or reserved functions. When a capacity report lists reserved capacity, that amount is deliberately excluded from the free value, so total minus used will overstate available space. The reserved portion protects operational needs such as metadata, snapshot growth, and maintenance headroom, depending on the container configuration. Replication factor is wrong because RF multiplies stored data into used capacity; it does not create a separate reserved pool that explains a gap between total, used, and free. Compression and deduplication are wrong because they reduce the amount of physical capacity attributed to used data after savings, but they do not reserve free space for operations. Capacity runway forecasting is wrong because it predicts future exhaustion from historical growth and does not alter the current free-capacity calculation. Exam caveat: on the exam, reserved capacity means capacity that is present but not usable as free space, not a failed reclamation job or a forecast delay. Operational check: compare total, used, free, and reserved capacity in Prism Central, then verify capacity reservation and snapshot usage before raising a capacity ticket.