File system growth management strategies can be summarized as follows:
- Auto-expansion enabled, but not confined. The file system is created with a defined size limit, and a small amount of that space is actually allocated when the file system is created. The file system is then allowed to expand automatically (auto-expansion enabled) until the storage pool hosting the file system is full (auto-expansion is not confined), as long as the file system expansion will not cause the file system to exceed the maximum allowable number of chunks in a file system.
- Auto-expansion enabled, and confined. The file system is created with a defined size limit, and a small amount of that space is actually allocated when the file system is created. The file system is then allowed to expand automatically (auto-expansion enabled) to the defined size limit (auto-expansion is confined), as long as there is available space in the storage pool and the file system expansion will not cause the file system to exceed the maximum allowable number of chunks in a file system.
- Auto-expansion disabled. The file system is created with the full amount of the specified size, and is not allowed to expand automatically (auto-expansion disabled).
| File System Type | Auto-Expansion Enabled | Auto-Expansion Disabled |
|---|---|---|
| Untiered |
If auto-expansion is not confined, the size limit is ignored. The file system will be allowed to expand until the storage pool is full. If auto-expansion is confined, the size limit defines the maximum size to which a file system will be allowed to expand. When the file system is created, it is initially allocated a certain amount of space (the initial capacity), and the file system is allowed to expand automatically, up to its size limit. When the file system uses approximately 80% of its currently allocated space, it is expanded automatically up to its size limit. This expansion occurs in increments specified by the guideline chunk size (which is calculated by the system). The file system can be manually expanded, increasing the file system size limit. |
The size limit defines the amount of space that is immediately allocated to the file system. When the file system is created, it is allocated the total amount of space specified by the size limit. The file system can be manually expanded, increasing the file system size limit. |
| Tiered |
If auto-expansion is not confined, the size limit is ignored if defined. The tiers of the file system will be allowed to expand until the storage pool is full. If auto-expansion is confined, the size limit defines the maximum size to which the tier of a file system will be allowed to expand. When the file system is created, the user data tier is initially allocated a certain amount of space (the initial capacity), and the user data tier is allowed to expand automatically, up to its size limit. When the user data tier uses approximately 80% of its currently allocated space, it is expanded automatically up to its size limit. This expansion occurs in increments specified by the guideline chunk size (which is calculated by the system). Either tier can be manually expanded, increasing the file system size limit. When the file system is created, the user data tier is initially allocated the total amount of space specified by the size limit. Either tier can be manually expanded, increasing the file system size limit. |
The size limit defines the amount of space that is immediately
allocated to the user-data tier.
When the file system is created, the user data tier is initially allocated the total amount of space specified by the size limit. Either tier can be manually expanded, increasing the file system size limit. |
- Confined limit not reached (only for file systems that have auto-expansion confined). As long as the file system expansion would not exceed the confined auto-expansion limit.
- Available space. Sufficient available free space and chunks remain in the storage pool.
- Chunk limit. The file system expansion will not cause the file system to exceed the maximum allowable number of chunks in a file system.
- Maximum supported file system size. The file system expansion will not cause the file system to exceed the maximum supported file system size.
Whether auto-expansion is enabled or disabled, you can limit the size of the file system of an untiered file system or either tier of a tiered file system. If necessary, you can manually expand the file system or of an untiered file system or a tier of a tiered file system.
Note: File system auto-expansion may be enabled or disabled for all file systems in a particular storage pool. When enabled for a storage pool, file system auto-expansion is enabled by default, but if it has been disabled on an individual file system, you can re-enable it. When file system auto-expansion is disabled for a storage pool, you cannot enable it (you must expand the file system manually).