SCU (Storage Capacity Unit)

Purchase method

Offset factors

The following table lists the SCU offset factors for different OSS storage classes in the Chinese mainland.

Offset order

OSS storage fees are offset in the following order: region-specific storage plans, general-purpose storage plans for the Chinese mainland, and finally SCUs. Any remaining storage usage is billed at the pay-as-you-go rate.

FAQ

Why do OSS storage fees stay the same after I purchase an SCU?

An SCU is a general-purpose capacity plan that works across multiple cloud storage products. The capacity of one SCU is consumed by every product in the same region that supports SCU offsetting, so OSS does not have exclusive use of it. If another product in the same region holds a large amount of storage, such as ECS snapshots, that product can consume the SCU capacity in full. No SCU capacity then remains for your OSS storage, and your bill shows unchanged OSS storage fees.

An SCU also offsets storage capacity fees only. Other OSS billable items, such as outbound traffic and requests, fall outside the scope of SCU offsetting, so those fees do not drop after you purchase an SCU.

How do I check which products consumed the SCU capacity?

Log on to Expenses and Costs, open the Resource Instance Management page, find the SCU instance, and view its offset details. The offset details show how much SCU capacity OSS consumed and how much other products, such as ECS snapshots, consumed. Use these figures to confirm whether any SCU capacity was applied to OSS.

How do I reduce OSS bills when other products have consumed all the SCU capacity?

• Stack another SCU. An SCU supports stacking, so you can purchase more than one SCU for the same region and effective period to raise the total capacity available for offsetting.

• Purchase a dedicated resource plan for the OSS billable item you want to cover, such as an outbound data transfer plan, a request plan, or an Archive storage plan. A dedicated resource plan covers billable items that an SCU cannot offset or for which no SCU capacity remains.

Use the offset details from the previous question to identify the billable item that accounts for the gap, and then select the matching resource plan.

Example

In June 2021, a user purchased a 500 GB Standard (LRS) storage plan and a 20 GB SCU in the China (Hangzhou) region. During that month, the user stored 600 GB of Standard LRS objects and 200 GB of Archive LRS objects in the same region. The following table describes how the storage fees are offset.

More information

If your OSS usage involves only Standard LRS storage, you can also use Reserved Capacity to offset your fees.

For more information, see Reserved Capacity.