Figure 48 SRDF/AR 3-site solution
SRDF/S
Site A
Site C
Host
Site B
R1
R2
Host
TimeFinder
R1
TimeFinder
SRDF adaptive
copy
R2
If Site A (primary site) fails, the R2 device at Site B provides a restartable copy with
zero data loss. Site C provides an asynchronous restartable copy.
If both Site A and Site B fail, the device at Site C provides a restartable copy with
controlled data loss. The amount of data loss is a function of the replication cycle time
between Site B and Site C.
SRDF and TimeFinder control commands to R1 and R2 devices for all sites can be
issued from Site A. No controlling host is required at Site B.
Use SRDF/AR 3-site solutions to:
l
Reduce required network bandwidth using incremental resynchronization between
the secondary SRDF target site and the tertiary SRDF target site.
l
Reduce network cost and improve resynchronization time for long-distance SRDF
implementations.
l
Provide disaster recovery testing, point-in-time backups, decision support
operations, third-party software testing, and application upgrade testing or the
testing of new applications.
Requirements/restrictions
In a 3-site SRDF/AR multi-hop solution, SRDF/S host I/O to Site A is not
acknowledged until Site B has acknowledged it. This can cause a delay in host
response time.
TimeFinder and SRDF/A
In SRDF/A solutions, device-level pacing:
l
Prevents cache utilization bottlenecks when the SRDF/A R2 devices are also
TimeFinder source devices.
l
Allows R2 or R22 devices at the middle hop to be used as TimeFinder source
devices.
Device-level (TimeFinder) pacing
on page 134 provides more information.
Note
Device-level write pacing is not required in configurations that include Enginuity 5876
and HYPERMAX OS.
Blended local and remote replication
162
Product Guide
VMAX 100K, VMAX 200K, VMAX 400K with HYPERMAX OS
Содержание VMAX 100K
Страница 1: ...EMC VMAX3 Family Product Guide VMAX 100K VMAX 200K VMAX 400K with HYPERMAX OS REVISION 6 5 ...
Страница 20: ...Preface 20 Product Guide VMAX 100K VMAX 200K VMAX 400K with HYPERMAX OS ...
Страница 46: ...VMAX3 with HYPERMAX OS 46 Product Guide VMAX 100K VMAX 200K VMAX 400K with HYPERMAX OS ...
Страница 72: ...Open systems features 72 Product Guide VMAX 100K VMAX 200K VMAX 400K with HYPERMAX OS ...
Страница 82: ...Provisioning 82 Product Guide VMAX 100K VMAX 200K VMAX 400K with HYPERMAX OS ...
Страница 100: ...Native local replication with TimeFinder 100 Product Guide VMAX 100K VMAX 200K VMAX 400K with HYPERMAX OS ...
Страница 158: ...Remote replication solutions 158 Product Guide VMAX 100K VMAX 200K VMAX 400K with HYPERMAX OS ...
Страница 186: ...Mainframe Error Reporting 186 Product Guide VMAX 100K VMAX 200K VMAX 400K with HYPERMAX OS ...
Страница 200: ...Licensing 200 Product Guide VMAX 100K VMAX 200K VMAX 400K with HYPERMAX OS ...