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 GB.
- StorageUsed: The maximum amount of space used during the interval in GB.
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 8-2 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.