Home > Storage > PowerScale (Isilon) > Product Documentation > Storage (general) > Storage Quota Management and Provisioning with Dell PowerScale SmartQuotas > Architectural overview
The following table shows the primary elements of SmartQuotas, from the file system point of view:
Element | Description |
Domain | The files and directories that belong to a quota. |
Resource | The quantity that is limited. |
Enforcement | Quota limits and what actions are taken when those thresholds are exceeded. |
Each quota domain includes usage levels, limits, and configuration options. Most of this information is organized and managed by the file system and stored in the quota database. This database is represented in a B-tree structure, which is known as the quota tree, and provides both scalability and fast random access. Because of its importance, the quota database is protected at the highest level for metadata in OneFS. The quota accounting blocks (QABs) within individual records are protected at the same level as the associated directory.
The following table outlines the principal parts of a quota domain:
Component | Description |
Quota domain key | Where the unique identifier for the domain is stored. |
Quota domain header (QDH) | Contains various state and configuration information that affects the domain as a whole. |
Quota domain enforcements | Manages quota limits, including whether they have been reached or exceeded, notification information, and the quota grace period. |
Quota domain account (QDA) | Handles tracking of usage levels for the domain. The QDA tracks physical, logical, and file resource types for each domain. |