A copy cannot be executed if another function is running in the storage system or the target volume. For details
on the functions that can be executed simultaneously, refer to
"Combinations of Functions That Are Available for
Simultaneous Executions" (page 214)
Backup (SAN)
Local Copy
The Advanced Copy functions offer the following copy methods: "Mirror Suspend", "Background Copy", and "Copy-
on-Write". The function names that are given to each method are as follows: "EC" for the "Mirror Suspend" meth-
od, "OPC" for the "Background Copy" method, and "SnapOPC" for the "Copy-on-Write" method.
When a physical copy is performed for the same area after the initial copy, OPC offers "QuickOPC", which only
performs a physical copy of the data that has been updated from the previous version. The function
only copies data that is to be updated and performs generation management of the copy source volume.
●
OPC
All of the data in a volume at a specific point in time is copied to another volume in the ETERNUS DX.
OPC is suitable for the following usages:
•
Performing a backup
•
Performing system test data replication
•
Restoring backup data (restoration after replacing a drive when the copy source drive has failed)
●
QuickOPC
QuickOPC copies all data as initial copy in the same way as OPC. After all of the data is copied, only updated data
(differential data) is copied. QuickOPC is suitable for the following usages:
•
Creating a backup of the data that is updated in small amounts
•
Performing system test data replication
•
Restoration from a backup
●
SnapOPC/ (*1)
As updates occur in the source data, SnapOPC/ saves the data prior to change to the copy destination
(SDV/TPV/FTV). The data, prior to changes in the updated area, is saved to an SDP/TPP/FTRP. Create an SDPV for
the SDP when performing SnapOPC/ by specifying an SDV as the copy destination.
SnapOPC/ is suitable for the following usages:
•
Performing temporary backup for tape backup
•
Performing a backup of the data that is updated in small amounts (generation management is available for
)
•
SnapOPC/ operations that use an SDV/TPV/FTV as the copy destination logical volume have the fol-
lowing characteristics. Check the characteristics of each volume type before selecting the volume type.
Table 31 Characteristics of SnapOPC/ Operations with Each Type of Copy Destination Logical Volume
Item to compare
SDV
TPV/FTV
Ease of operation set-
tings
The operation setting is complex because a
dedicated SDV and SDP must be set
The operation setting is easy because a dedicated SDV
and SDP are not required
Usage efficiency of the
pool
The usage efficiency of the pool is higher
because the allocated size of the physical
area is small (8KB)
The usage efficiency of the pool is lower because the al-
located size of the physical area is large with a chunk
size of 21MB / 42MB / 84MB / 168MB
2. Basic Functions
Backup (Advanced Copy)
91
FUJITSU Storage ETERNUS DX500 S4/DX600 S4, ETERNUS DX500 S3/DX600 S3 Hybrid Storage Systems Design Guide (Basic)
Copyright 2019 FUJITSU LIMITED
P3AM-7722-25ENZ0
Содержание ETERNUS DX500 S3/DX600 S3
Страница 218: ......