Local Copy - Fujitsu ETERNUS DX80 S2 Overview

Chapter 6 Optional Functions
6.2 Backup (Advanced Copy)
6.2.1

Local Copy

The Advanced Copy functions offer the following copy methods: "Mirror Suspend", "Background Copy", and
"Copy-on-Write". The "Equivalent Copy (EC)" function uses the "Mirror Suspend" method, the "One Point Copy
(OPC)" function uses the "Background Copy" method, and the "SnapOPC" function uses the "Copy-on-Write"
method.
There is also a "QuickOPC" function for the OPC method, which only copies data that has been updated since
the previous update. The SnapOPC+ function only copies data that is to be updated and performs generation
management of the copy source volume.
●
OPC (One Point Copy)
One Point Copy (OPC) is a function that copies data in the volume to another volume in the ETERNUS DX
Disk storage system at a specific point in time.
OPC is suitable for the following usages:
- Performing a backup
- Performing system test data replication
- Restoring backup data (restoration after replacing a disk when the copy source disk has failed)
●
QuickOPC
QuickOPC copies all data as initial copy in the same way as OPC. After the initial copy has completed, only
updated data (differential data) is copied. QuickOPC is suitable for the following usages:
- Performing a backup of data that is not updated regularly
- Performing system test data replication
- Restoration from a backup
●
SnapOPC/SnapOPC+ (*1)
As updates occur in the source data, SnapOPC/SnapOPC+ saves the data prior to change to the copy
destination (Snap Data Volume (SDV)). Prepare a Snap Data Pool (SDP) before performing SnapOPC/
SnapOPC+. When an amount of data that exceeds the SDV capacity is saved, volumes are supplied from a
SDP. SnapOPC/SnapOPC+ is suitable for the following usages:
- Performing temporary backup for tape backup
- Performing a backup of data that is not updated regularly (generation management is available for
SnapOPC+)
*1: The difference between SnapOPC and SnapOPC+ is that SnapOPC+ manages the history of updated data as
opposed to SnapOPC. While SnapOPC manages the updated data in units of sessions and saves the same
data redundantly, SnapOPC+ has updated data as history information and can provide multiple generation-
backups.
●
EC (Equivalent Copy)
EC makes a mirror copy of the copy source to the copy destination beforehand, and then suspends the copy
and treats all data as independent data.
When copying is resumed, only updated data in the copy source is copied to the copy destination. If the
copy destination data has been changed, copy the copy source data again. EC is suitable for the following
usages:
- Performing a backup
- Performing system test data replication
82
ETERNUS DX80 S2/DX90 S2 Disk storage system Overview
Copyright 2013 FUJITSU LIMITED P3AM-4812-11ENZ0