HP StorageWorks 1500cs Modular Smart Array - Manual (Page 57)

Using the Command Line Interface 57
Setting the preferred path mode
The preferred path mode determines how I/O traffic to the logical drives is managed on controllers that
are in an active/active configuration.
• In Automatic mode, the storage system automatically selects a suitable path for I/O traffic to each
logical drive depending on the host I/O patterns at the time. Because the optimum path can vary
with time, I/O traffic for any given logical drive can be directed through either controller.
• In Manual mode, all I/O traffic to a given logical drive is directed through a designated controller.
In this case, you must also specify the preferred controller for each logical drive ("
Assigning a
redundant controller to a logical drive " on page 57 ).
Syntax:
<target> modify [preferredpathmode=automatic|manual|?]
where <target> is a redundant controller.
Example command:
controller ch="lab 3" modify ppm=manual
Assigning a redundant controller to a logical drive
When you have set the preferred path mode (" Setting the preferred path mode " on page 57 ) in a
redundant system to Manual, you must use the chassisslot command to assign each logical drive in
the system to one of the redundant controllers.
Syntax:
<target> modify [chassisslot=#|?]
where <target> is a valid logical drive on a controller that is in an active/active configuration and #
denotes the chassis slot number of the redundant controller. (To obtain the chassis slot number, use the
show command on the controller.)
Example command:
controller ch="lab 3" ld 1 modify chs=2
Rescanning the system
A rescan detects devices that have been added to the system since the previous rescan or since the ACU
CLI was started, whichever is more recent.
Syntax:
Use the word rescan directly at the ACU CLI prompt, without any target device or parameters.
Example command:
=> rescan