HP XP P9500 Storage User Manual
Page 53
There are five types of 3DC configurations:
•
3DC Cascade (Cnt Ac-S Z x Cnt Ac-J Z) configuration
•
3DC Cascade (Cnt Ac-J Z x Cnt Ac-J Z) configuration
•
3DC Multi-Target (Cnt Ac-S Z x Cnt Ac-J Z) configuration
•
3DC Multi-Target (Cnt Ac-J Z x Cnt Ac-J Z) configuration
•
Delta Resync configuration
3DC (Cnt Ac-J Z x Cnt Ac-J Z) configuration is a generic term used to refer to 3DC Cascade (Cnt
Ac-J Z x Cnt Ac-J Z) configurations and 3DC Multi-Target (Cnt Ac-J Z x Cnt Ac-J Z) configurations.
provides an overview of the 3DC configurations. Select the configuration that
is most appropriate to your needs.
Table 11 Overview of each 3DC configuration
Characteristics
Connection type
Configuration name
Primary
→ Intermediate (nearby) → Remote
(distant)
3DC Cascade (Cnt
Ac-S Z x Cnt Ac-J Z)
configuration
•
Because data is remotely copied through
the intermediate site, the remote site can
be at a more distant place.
•
Cnt Ac-S Z x Cnt Ac-J Z: Because
Continuous Access Synchronous Z
Primary
→ Intermediate (distant) → Remote
(distant)
3DC Cascade (Cnt
Ac-J Z x Cnt Ac-J Z)
configuration
performs operations from the primary site
to the intermediate site, the updating of
data between the two sites is essentially
instantaneous.
•
Cnt Ac-J Z x Cnt Ac-J Z: Because
Continuous Access Journal Z performs
operations from the primary site to the
intermediate site, the I/O load on the host
is low.
Primary
→ Local (nearby)
3DC Multi-Target
(Cnt Ac-S Z x Cnt
•
Because the data can be remotely copied
from the primary site to two sites at the
Primary
→ Remote (distant)
Ac-J Z)
configuration
same time without using an intermediate
site, the time lag between sites is low.
•
If a disaster occurs at a site other than the
primary site, the configuration can be
changed to a 2DC configuration by
Primary
→ Remote 1 (distant)
3DC Multi-Target
(Cnt Ac-J Z x Cnt
performing a remote copy between the
remaining sites.
Primary
→ Remote 2 (distant)
Ac-J Z)
configuration
•
Cnt Ac-S Z x Cnt Ac-J Z: Because
Continuous Access Synchronous Z
performs operations from the primary site
to the local site, the updating of data
between the primary site and the local site
is essentially instantaneous.
•
Cnt Ac-J Z x Cnt Ac-J Z: Because
Continuous Access Journal Z performs
operations from the primary site to both
remote sites, the I/O load on the host is
low.
In addition to the characteristics of 3DC
Multi-Target (Cnt Ac-S Z x Cnt Ac-J Z)
Primary
→ Local (nearby)
1
Primary
→ Remote (distant)
1
Delta Resync
configuration
configurations, if a storage system failure
occurs at the primary site, the configuration
can be changed to a 2DC configuration by
performing a Delta Resync (which copies only
differential data).
Replication products and data center configurations
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