Host Machines That Can Be Paired - Hitachi VSP F1500 User And Reference Manual

storage systems in different geographic areas. Each CCI instance has its
own operation manager, server software, and scripts and commands, and
each CCI instance communicates independently with the command
device. Each RAID storage system has a command device that
communicates with each CCI instance independently. Each storage
system contains the primary volumes of its connected CCI instance and
the secondary volumes of the other CCI instance (located on the same
host in this case).
• Two hosts connected to one storage system. Having two attached hosts
to one storage system, one host for the primary volume and the other
host for the secondary volume, allows you to maintain and administer the
primary volumes while the secondary volumes can be taken offline for
testing. The CCI instances of separate hosts are connected via the LAN so
that they can maintain awareness of each other. The RAID storage
system contains the command device that communicates with both CCI
instances (one on each host) and the primary and secondary volumes of
both CCI instances
• Two hosts connected to two storage systems. Two hosts connected to two
storage systems also allows the most flexible disaster recovery plan,
because both sets of data are administered by different hosts. This guards
against storage system failure as well as host failure.The CCI instances of
separate hosts are connected via the LAN so that they can maintain
awareness of each other. Each RAID storage system has a command
device that communicates with each CCI instance independently. Each
storage system contains the primary volumes of its connected CCI
instance and the secondary volumes of the other CCI instance (located on
a different host in this case).

Host machines that can be paired

When you perform a pair operation, the version of CCI should be the same on
the primary and secondary sites. As a particular application uses HORC, users
sometimes use a HORC volume as the data backup volume for the server. In
this case, CCI requires that the CCI instance correspond to each OS platform
that is located on the secondary site for the pair operation of data backup on
the primary servers of each OS platform.
However, it is possible to prepare only one server at a secondary site by
supporting CCI communications among different OSs (including the converter
for little-endian vs. big-endian).
Figure 2-10 CCI communication among different operating systems on page
2-13 represents CCI's communication among different OSs, and
Supported CCI (HORCM) communication on page 2-13
communication (32-bit, 64-bit) among different OSs. Please note the
following terms that are used in the example:
• RM-H: Value of HORCMFCTBL environment variable for an HP-UX CCI
instance on Windows
• RM-S: Value of HORCMFCTBL environment variable for a Solaris CCI
instance on Windows
2-12
CCI software environment
Command Control Interface User and Reference Guide
Table 2-1
shows the supported