OSS provides two storage redundancy types: zone-redundant storage (ZRS) and locally redundant storage (LRS). These types employ data redundancy mechanisms across single or multiple availability zones to ensure data durability and service availability.
Zone-redundant storage (ZRS)
For regions with three or more availability zones, the multi-zone redundancy storage mechanism is implemented. Multiple copies of your data are stored across multiple zones in the same region, ensuring uninterrupted access even if one zone becomes unavailable. For regions with two availability zones, the dual-zone redundancy storage mechanism is implemented. Copies of your data are redundantly stored across the two zones within the same region, ensuring uninterrupted access even if one zone becomes unavailable.
Zone-redundant storage (ZRS) provides redundancy within a single region. If the entire region becomes unavailable, the data will be inaccessible. For businesses that require extremely high availability, use cross-region replication to back up your data.
Locally redundant storage (LRS)
LRS stores your data redundantly on multiple devices across different facilities within a single availability zone (AZ). This ensures data durability and service availability in the event of a hardware failure.
LRS provides data redundancy within a specific AZ. If the AZ becomes unavailable, your data is inaccessible. For higher availability, use zone-redundant storage (ZRS).
Storage redundancy comparison
The following table compares the data durability and service availability of locally redundant storage and zone-redundant storage.
Storage redundancy type | Storage class | Region | Data durability | Service availability |
Zone-redundant storage | Standard | China (Hangzhou), China (Shanghai), China (Beijing), China (Zhangjiakou), China (Ulanqab), China (Shenzhen), China (Hong Kong), Japan (Tokyo), Singapore, Indonesia (Jakarta), Malaysia (Kuala Lumpur), Germany (Frankfurt) | 99.9999999999% (12 nines) | 99.995% |
US (Silicon Valley), US (Virginia), Philippines (Manila), Thailand (Bangkok), South Korea (Seoul), UAE (Dubai), UK (London), Malaysia (Johor), France (Paris) | 99.99% | |||
Infrequent Access | China (Hangzhou), China (Shanghai), China (Beijing), China (Zhangjiakou), China (Ulanqab), China (Shenzhen), China (Hong Kong), Japan (Tokyo), Singapore, Indonesia (Jakarta), Malaysia (Kuala Lumpur), Germany (Frankfurt) | 99.50% | ||
Archive Storage | ||||
Locally redundant storage | Standard | All public cloud regions | 99.999999999% (11 nines) | 99.99% |
Infrequent Access | 99% | |||
Archive Storage | ||||
Cold Archive | China (Hangzhou), China (Shanghai), China (Qingdao), China (Beijing), China (Zhangjiakou), China (Hohhot), China (Ulanqab), China (Shenzhen), China (Heyuan), China (Guangzhou), China (Chengdu), China (Hong Kong), US (Silicon Valley), US (Virginia), Mexico, Japan (Tokyo), Singapore, Malaysia (Kuala Lumpur), Indonesia (Jakarta), Philippines (Manila), Germany (Frankfurt), UK (London), UAE (Dubai) | |||
Deep Cold Archive | China (Hangzhou), China (Shanghai), China (Beijing), China (Zhangjiakou), China (Ulanqab), China (Shenzhen), Singapore |
Related operations
To create a bucket that uses zone-redundant storage, see Create a bucket that uses zone-redundant storage.
To convert a bucket's storage redundancy type from LRS to ZRS, see Convert the storage redundancy type of a bucket.