HP XP P9500 Storage - Manual (Page 40)

Example 3 Setting example of virtual command device in configuration definition file (out-of-band
method)
HORCM_CMD
#dev_name dev_name dev_name
\\.\IPCMD-192.168.1.100-31001
About alternate command devices
If RAID Manager receives an error notification in reply to a read or write request to a command
device, the RAID Manager software can switch to an alternate command device, if one is defined.
If a command device is unavailable (for example, blocked due to online maintenance), you can
switch to an alternate command device manually. If no alternate command device is defined or
available, all commands terminate abnormally, and the host cannot issue RAID Manager commands
to the storage system. To ensure that RAID Manager operations continue when a command device
becomes unavailable, you should set one or more alternate command devices.
Because the use of alternate I/O pathing depends on the platform, restrictions are placed upon
it. For example, on HP-UX systems only devices subject to the LVM can use the alternate path
PV-LINK. To prevent command device failure, RAID Manager supports an alternate command
device function.
•
Definition of alternate command devices. To use an alternate command device, define two or
more command devices for the HORCM_CMD item in the configuration definition file. When
two or more devices are defined, they are recognized as alternate command devices. If an
alternate command device is not defined in the configuration definition file, RAID Manager
cannot switch to the alternate command device.
•
Timing of alternate command devices. When the HORCM receives an error notification in
reply from the operating system via the raw I/O interface, the command device is alternated.
It is possible to alternate the command device forcibly by issuing an alternating command
provided by Continuous Access Synchronous (horcctl -C).
•
Operation of alternating command. If the command device is blocked due to online
maintenance (for example, microcode replacement), the alternating command should be issued
in advance. When the alternating command is issued again after completion of the online
maintenance, the previous command device is activated again.
•
Multiple command devices on HORCM startup. If at least one command device is available
during one or more the command devices that was described to the configuration definition
file, then HORCM starts with a warning message to startup log by using available command
device. The user needs to confirm that all command devices can be changed by using horcctl
-C command option, or HORCM has been started without warning message to the HORCM
startup log.
Figure 8 Alternate command device function
40 Installing and configuring RAID Manager