Glossary
Storage pooling
Storage pooling combines the capacity of many drives, arrays or servers into a single shared supply that volumes, shares or buckets draw from as data arrives. It ends free space stranded in separate silos and spreads work across more drives, while tying every workload on the pool to the same limits.
Stranded space and what pooling releases
Separate systems each keep free space that only they can use. One application runs out while the system beside it sits more than half empty, and the only fix is buying more. A pool tracks free space centrally and hands it to whichever workload writes next, so the organization buys for total demand rather than for the peak of each silo.
Where pooling happens
| Level | What is pooled | Typical boundary |
|---|---|---|
| Inside one array | Drives behind the array controllers | The array itself |
| Storage virtualization | Several arrays under one management layer | The arrays the layer can reach |
| Scale-out cluster | Drives across many servers | Grows as servers are added |
| Cloud storage | A provider's capacity, metered per use | The account or region |
Object storage works as a single pool by default, which is one reason it suits large, mixed estates.
What every tenant shares
A pool that fills blocks writes for everyone on it. Quotas limit what one team may consume but create no space, and when quotas add up to more than the pool holds, a single runaway ingest stops every team at once. Reads usually continue, but backups, new uploads and log writes all halt together. Performance is shared too: a heavy job on the same drives slows its neighbours unless storage QoS limits keep them apart. Thin provisioning sharpens both risks, because the space promised to volumes exceeds what the pool physically holds.
Alerts set by delivery time
The useful alert threshold on a pool is not a fixed percentage. It is the point at which the remaining space, at the current growth rate, lasts as long as it takes to approve, ship and install more hardware. A pool at 70 percent can be weeks from full when a large ingest starts, and one at 85 percent can be safe for months if growth is flat.