Enabling or Disabling Automatic Storage Expansion
Enable automatic storage expansion on your DB system to avoid lost of service when the allocated storage space gets filled up.
Note
You cannot enable automatic storage expansion on an Always Free DB system.
You cannot enable automatic storage expansion on an Always Free DB system.
You can use the following metrics to monitor the storage space of a DB system:
- StorageAllocated: The maximum amount of space allocated to the DB system during the interval in GiB.
- StorageUsed: The maximum amount of space used during the interval in GiB.
If automatic storage expansion is enabled, it will expand the storage size of a
DB system when
StorageUsed >= StorageAllocated - MIN(50, 8 + (StorageAllocated) ÷ 25)
It will expand the storage size by increasing the
StorageAllocated:StorageAllocated = StorageAllocated + MIN(50, 8 + (StorageAllocated) ÷ 25)The
expanded storage size will become the current storage size to compute the
threshold for the next storage expansion when the free storage space becomes
low again. After the storage size has reached the specified maximum storage
size, it will not expand the storage size further.Table 8-19 This table shows some examples of the computation of the StorageUsed that triggers the storage expansion.
| StorageAllocated | When StorageUsed hits | StorageAllocated after expansion |
|---|---|---|
| 50 | 50 - 10 = 40 | 50 + 10 = 60 |
| 100 | 100 - 12 = 88 | 100 + 12 = 112 |
| 200 | 200 - 16 = 184 | 200 + 16 = 216 |
| 500 | 500 - 28 = 472 | 500 + 28 = 528 |
| 800 | 800 - 40 = 760 | 800 + 40 = 840 |
| 1000 | 1000 - 48 = 952 | 1000 + 48 = 1048 |
| 1050 | 1050 - 50 = 1000 | 1050 + 50 = 1100 |
| 1100 | 1100 - 50 = 1050 | 1100 + 50 = 1150 |
You can build a chart to monitor the metrics over a period of time and identify whether the value has changed or when the value has changed. See Using Metrics to Create Queries. If needed, you can also create an alarm based on the metrics. See Using Metrics to Create Alarms.
Use one of the following method to enable or disable automatic storage
expansion:
- Using the Console
- Using the REST API, run the UpdateDbSystem
operation with the
dataStorageattribute.