Administrator’s Command Line Guide

3.1. About Object Storage
of small objects as even a 1-byte object will occupy a 4KB block. In addition, about 4KB of metadata per object
will be stored on NS. However, this approach allows achieving the maximum performance, eliminates free
space fragmentation, and offers guaranteed object insert performance. Moreover, the larger the object, the
less noticeable the overhead. Finally, when an object is deleted, its pool block is marked free and can be used
to store new objects.
Multi-part objects are stored as parts (each part being itself an object) that may be stored on different object
servers.
3.1.3.4 S3 Management Tools
Object storage has two tools:
• ostor for configuring storage components, and
• s3-ostor-admin for user management, an application that allows to create, edit, and delete S3 user accounts
as well as manage account access keys (create and delete paired S3 access key IDs and S3 secret access
keys).
3.1.3.5 Service Bucket
The service bucket stores service and temporary information necessary for the S3 storage. This bucket is only
accessible by the S3 admin (while the system admin would need access keys created with the s3-ostor-admin
tool). The information corresponds to the following names in the object storage:
• Names with a /u/ prefix. Correspond to user data (user identifier, e-mail, access key ID, and secret access
key).
• Names with an /m/ prefix. Correspond to temporary information on current multipart uploads and their
parts.
• Names with a /tmp/ prefix. Correspond to information on operations that consist of several atomic alter-
ations of objects in the storage. These names are necessary in case the operation fails.
3.1.4 Data Interchange
In Acronis object storage, every service has a 64-bit unique identifier. At the same time, every object has a
unique name. The directory part of an object’s name determines a name server to store it, and the full object’s
21