Flexible scaling

Db2 on Cloud provides you with the ability to independently scale up compute cores and storage.

As the number of cores is increased, memory is also increased. The updating of resources can result in an outage that can last up to 20 minutes.

Storage cannot be scaled down once it has been increased.

Standard plan

The Standard plan deploys with 8 GB of RAM, and 20 GB of disk space. You can then scale your plan with the drop-down lists in the Db2 on Cloud console.

Memory can be scaled up or down by selecting the number of vCPU. The standard plan is a multitenaned plan and therefore has dedicated memory only.

Memory can be scaled in the following increments:

Table 1. Core/memory scaling increments
vCPU	Memory
2	8 GB
4	16 GB
8	32 GB
16	64 GB

Storage can be scaled up to a maximum of 4 TB.

To scale memory and storage from within the console, complete the following steps:

Select Administration from the left side menu.
Select the Compute & storage tab.
Select Edit under the Compute & storage resources.
Select the drop-down list for vCPU (for memory) or Units for storage to make changes.
Click Save.
Select Confirm if you are satisfied with the changes.

Figure 1. Standard plan scaling memory and storage

Confirm_changes — Figure 2. Confirm scaling changes for standard plan

Enterprise plan

Your Enterprise plan initially deploys with 4 cores, 16 GB of RAM, and 20 GB of disk space. You can then scale your plan with the drop-down lists in the Db2 on Cloud console.

Dedicated cores can be scaled up or down in the following increments with memory changing accordingly:

Table 2. Core/memory scaling increments
Cores	Memory
4	16 GB
8	32 GB
16	64 GB
32	128 GB
56	242 GB

When Storage is below 4 TB, it is scaled up in increments of 20 GB. When storage exceeds 4 TB, it will implement multiple disks. Each disk contains 4 TB storage; thus, in total, storage can be scaled up in increments of 4 TB as shown in the following example:

8 TB
12 TB
16 TB
20 TB
24 TB

Storage can be scaled up to a maximum of 24 TB.

To scale cores/memory and storage from within the console, complete the following steps:

Select Administration from the left side menu.
Select the Compute & storage tab.
Select Edit under the Compute & storage resources.
Select the drop-down list for vCPU (for memory) or Units for storage to make changes.
Click Save.
Select Confirm if you are satisfied with the changes.

Figure 3. Enterprise plan scaling cores/memory and storage

Scaling disk storage more than 4 TB

There may be an outage when tablespaces under the default storage group are rebalanced.

Rebalancing tablespaces can take several days to complete and can impact your performance.

Two new functions, Rebalance and Free space reclamation, are introduced to maximize the benefits of having multiple disks once you scale past 4TB.

Rebalance

The Rebalance functionality enables redistributing data which brings with it the benefit of striping data across multiple disks. When scaling storage past 4TB, tablespaces under the default storage group IBMSTOGROUP will be automatically rebalanced.

You are now given the option to rebalance any tablespaces from non-default storage groups after scaling is completed. A pop-up window will be presented to confirm rebalancing.

It is highly recommended to rebalance non-default storage groups after scaling past 4TB.

Figure 6. Confirm rebalance on tablespaces before scaling

Rebalance Status

To View the Rebalance status of tablespaces:

Select Data from Left Side
Click on the storage objects tab on top.

You can rebalance a tablespace individually on this tab.

Rebalance status — Figure 7. View rebalance status of tablespaces

Rebalance may impact your workload performance. Pause rebalance temporarily and resume it during an off-peak period if the rebalance affects your workload performance.

Resume_rebalance — Figure 9. Resume rebalance

Free space reclamation after rebalance

Reclaim freed space on disks after rebalancing by choosing the Reclaim space option as shown in the figure below. After the space is reclaimed, the reclaimable space will be updated to 0 GB in the reclaimable column.

Space_reclaimed — Figure 11. Freed disk space reclaimed