Administrator’s Command Line Guide

3.1. About Object Storage
Another feature of object storage is eventual consistency. Eventual consistency does not guarantee that
reads are to return the new state after the write has been completed. Readers can observe the old state for
an undefined period of time until the write is propagated to all the replicas (copies). This is very important for
storage availability as geographically distant data centers may not be able to perform data update
synchronously (e.g., due to network issues) and the update itself may also be slow as awaiting acknowledges
from all the data replicas over long distances can take hundreds of milliseconds. So eventual consistency
helps hide communication latencies on writes at the cost of the probable old state observed by readers.
However, many use cases can easily tolerate it.
3.1.1 Object Storage Infrastructure Overview
The object storage infrastructure consists of the following entities: object servers (OS), name servers (NS), S3
gateways (GW), and the block-level backend.
These entities run as services on the Acronis Storage nodes. Each service should be deployed on multiple
Acronis Storage nodes for high availability.
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