Storage capacity units (SCUs) are subscription storage resource plans that can be used to offset the storage fees of various Alibaba Cloud storage services. Compared with storage plans that are dedicated to specific storage services, SCUs are more flexible and cost-effective.
Supported services
SCUs are measured by capacity. An SCU can have a capacity of 20 GiB, 40 GiB, 100 GiB, 200 GiB, 500 GiB, 1 TiB, 2 TiB, 5 TiB, 10 TiB, 20 TiB, or 50 TiB. Different capacities are suited for different scenarios from daily use by developers to enterprise-level applications.
The following section describes the services whose storage fees can be offset by SCUs:
SCUs can be used to offset the storage fees of enhanced SSDs (ESSDs), standard SSDs, ultra disks, and basic disks. SCUs cannot be used to offset the storage fees of local disks. For more information, see Offset rules for EBS.
SCUs can be used to offset the storage fees of Object Storage Service (OSS) Standard, Infrequent Access (IA), and Archive objects. For more information, see Offset rules for OSS
SCUs can be used to offset the storage fees of Capacity and Performance NAS file systems. SCUs cannot be used to offset the storage fees of Extreme NAS file systems or IA Storage Media. For more information, see Offset rules for NAS.
SCUs can be used to offset the storage fees of snapshots. For more information, see Offset rules for the snapshot service.
Billing rules
SCUs support the subscription billing method. You are charged based on the capacity and validity periods of SCUs. For more information, see Purchase an SCU.
Usage notes
Before an SCU expires
After you purchase an SCU in a region, the SCU automatically matches eligible pay-as-you-go storage resources within that region to offset their bills until the SCU expires. When the deductible used capacity exceeds the SCU capacity, the excess capacity is billed on a pay-as-you-go basis.
After an SCU expires
After an SCU expires, you cannot use it to offset the bills of pay-as-you-go storage resources. If you have no other SCUs within the same region as the expired SCU, the pay-as-you-go storage resources are billed on a pay-as-you-go basis.