Terminology

Backup

A backup is a copy of a system, parts of a system, or files and folders, created automatically by software or manually by a user. The duplicate comprises a data set that is periodically transferred to a storage independent of the original storage and kept there for a defined time and usually in several versions from different points in time. From these copies, a system or a data set can be restored if it has been intentionally or unintentionally deleted, destroyed, modified or compromised.

Application-Aware Backup

Backup of a machine with special attention to the consistency of an application, e.g. a database or Exchange. This method of backup ensures that the application is set to a consistent state before the backup and that the backed up state can also be restored to a working state. In most cases, this procedure also includes the ability to restore individual data sets or individual data within the application.

File-level Backup

Backup of files and folders within a file system. Today mostly no longer the primary method for backing up data, because it is based on whole files. If one byte in a file has changed, the entire file is backed up again.

Block Cloning

Block cloning is a method of storing data in different file systems - e.g. ReFS under Windows or XFS under Linux. Blocks that are already in the file system are not stored again, but only a link is set to the existing block. This saves immense amounts of I/O operations and storage space. However, read performance suffers somewhat because the links have to be tracked during reading to get to the corresponding data.

Changed Block Tracking

Changed Block Tracking (CBT) is an incremental backup technique that identifies changes in the data set at the block level of storage and copies only those blocks that have changed since the last backup.

Restore

Restore is the process of recovering data. The cause of a restore can be data loss due to various events such as hardware defects, human errors or disasters.

Retention

Retention describes the retention period of a backup on the backup storage. It can be described as the number of versions (restore points) that are kept before the oldest version is deleted or the number of days that a backup is kept.

RPO

Recovery Point Objective (RPO) is the age of the files that must or can be recovered from the backup storage so that normal operation can be resumed after a failure. It denotes the maximum period of data loss in the event of a system failure, e.g. in the case of daily backup, up to 24 hours of data loss can occur if the system fails and has to be restored exactly before the next backup.

RTO

Recovery Time Objective (RTO) refers to the time required to recover a system or application, or the time period agreed with the customer that is acceptable to the customer.

Stage

Staging describes a step in the workflow in the context of most development projects. In our environments, it denotes the status of a system - e.g. production, test, development, ...

SLA

A Service Level Agreement (SLA) is a framework contract concluded between a service provider and a customer to define the quality of a recurring service.