The server can monitor space allocation on a file system and trigger alerts when pre-set thresholds are reached; optionally, users can be prevented from creating more files once a threshold has been reached. Alternatively, the file system can be expanded either manually or automatically while online. The command fs-usage controls the monitoring. See the man pages for details.
Two activities consume system space:
- Live file system. Refers to the space consumed when network users add files or increase the size of existing files.
- Snapshots. Refers to consistent file system images at specific points in time. Snapshots are not full copies of the live file system, and snapshot sizes change depending on the live file system. As the live file system uses more space, snapshots use more space, and as the data in the live file system is changed, snapshots require less space.
The server tracks space taken up by:
- The user data in the live file system
- The file system metadata (the data the server uses to manage the user data files)
- Snapshots
- Entire file system
| Warning | Severe | |
| Live file system | 70% | 90% |
| Snapshots | 20% | 25% |
| Entire file system | 90% | 95% |
When the storage space occupied by a volume crosses the warning threshold, a warning event is recorded in the event log. When the Entire File System Warning threshold has been reached, the space bar used to indicate disk usage turns yellow.
When the space reaches the severe threshold, a severe event is recorded in the event log, generating corresponding alerts. If the Entire File System Severe threshold has been reached, the space bar used to indicate disk usage turns amber.
If file system auto-expansion is disabled, you can limit the growth of the live file system to prevent it from crossing the severe threshold, effectively reserving the remaining space for use by snapshots. To limit the live file system to the percentage of available space defined as the severe threshold, fill the Do not allow the live file system to expand beyond its Severe limit check box on the File System Details page.