Object Storage Service (OSS) provides zone-redundant storage (ZRS) and locally redundant storage (LRS) to ensure data durability and availability. LRS provides data redundancy within one zone, and ZRS provides data redundancy across zones.
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.
ZRS stores multiple data copies across zones in a region. If the region becomes unavailable, your data is inaccessible. If your business application requires higher availability, we recommend that you use CRR to back up your data.
LRS
LRS stores multiple copies of your data on multiple devices of different facilities in the same zone. LRS provides data durability and availability even if hardware failures occur.
LRS stores multiple data copies in a single zone. If the zone becomes unavailable, data in the zone is inaccessible. If your business application requires higher availability, we recommend that you use ZRS instead.
Comparison of storage redundancy types
Below is the comparison between LRS and ZRS.
Storage redundancy type | Storage class | Region | Data durability | Availability |
ZRS | Standard | China (Hangzhou), China (Shanghai), China (Beijing), China (Zhangjiakou), China (Ulanqab), China (Shenzhen), China (Hong Kong), Japan (Tokyo), Singapore, Indonesia (Jakarta), Germany (Frankfurt) | 99.9999999999% (12 nines) | 99.995% |
Malaysia (Kuala Lumpur) | 99.99% | |||
Infrequent Access (IA) | China (Hangzhou), China (Shanghai), China (Beijing), China (Zhangjiakou), China (Ulanqab), China (Shenzhen), China (Hong Kong), Japan (Tokyo), Singapore, Indonesia (Jakarta), Germany (Frankfurt) | 99.50% | ||
Archive | ||||
LRS | Standard | All public cloud regions | 99.999999999% (11 nines) | 99.99% |
IA | 99% | |||
Archive | ||||
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), 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
You can specify ZRS as the storage redundancy type when you create a bucket. For information, see Create a zone-redundant storage bucket.
You can change the storage redundancy type of a bucket from LRS to ZRS.