Additional information about Dell ECS Object Storage high-availability features (such as multi-site replication) and expected availability in response to multiple component failures are described in detail in the Dell ECS: High Availability Design (H16344), available on the Dell ECS InfoHub.
Durability
Data durability of a storage system defines the expectations and probability for data being stored in the system without loss or corruption. Dell ECS Object Storage leverages a robust set of data integrity features including triple mirroring, 12+4 erasure coding, and checksum validation to deliver 8 9s (99.999999%) of durability for a single-site deployment. Where greater durability is required, Dell ECS Object Storage can be geo-replicated across multiple sites to achieve up to 11 9s (99.999999999%) of durability.
Availability
Data availability of a storage system defines the expectations and probability for the system to be able to successfully process data read/write requests. (Some factors that shape these estimates are outside the Dell ECS Object Storage solution itself, including data-center infrastructure failures or outages associated with dependent services). Dell ECS Object Storage delivers 99.999% availability (five 9s) based on request-error-rate estimates.