Qsan XCubeSAN XS5224D, Руководство пользователя

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Data Backup
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12. Data Backup
This chapter describes an overview and operations of data backup options in SANOS.
SANOS provides built-in data backup services for protecting data from most unpredictable
accidents including:

Volume snapshot which is described in the Managing Snapshots section.
 Local volume cloning which is described in the Manage Local Clones section.

Remote replication to have data duplicated to the remote sites, the function is described
in the
Managing Remote Replications section.
The DATA BACKUP function menu provides submenus of Snapshots and Replications .
Clone function is built in the Volumes function tab of the Volumes function submenu.
12.1. Managing Snapshots
A volume snapshot is based on copy-on-write technology. It’s a block-based and differential
backup mechanism. Snapshot functionality is designed to be highly efficient, it keeps a
point in time record of block-level, incremental data changes of the target LUN volume.
Snapshot can help recover a LUN volume to a previous state quickly to meet enterprise SLA
(Service Level Agreement) requirements of RPO (Recovery Point Objectives) and RTO
(Recovery Time Objective).
Snapshot is the easiest and most effective measure to protect against ransomware attacks,
virus attacks, accidental file deletion, accidental file modification, or unstable system
hardware caused by a bad I/O cable connection, unstable power supply… etc.
12.1.1. Theory of Operation
Snapshot-on-the-box captures the instant state of data in the target volume in a logical
sense. The underlying logic is copy-on-write, moving out the data which would be written to
certain location where a write action occurs since the time of data capture. The certain
location, named as “Snapshot Volume”, is essentially a new volume which can be attached
to a LUN provisioned to a host as a disk like other ordinary volumes in the system.