HP-UX Mass Storage Stack - Hardware Path Aliasing

3. The default hardware path alias is class instance # with no space between the two. For

example, fcd1.tport1.disk2. This is a component alias because it comes after the HBA and

target path in the hardware path and assumes both to already be aliased.

LUN objects

1. The saved hwp_abs_alias value is used (if it exists) as the absolute alias.

2. The saved hwp_comp_alias value is used (if it exists) as the component alias.

3. The saved alias attribute is used (if it exists) as the component alias.

4. The default hardware path alias is class instance # with no space between the two. For

example, disk2. This is an absolute alias because the LUN hardware path does not include the

other HBA, target path, or lunpath objects. Therefore, you can alias the entire hardware path.

Enabling and disabling the default scheme

The default scheme is enabled automatically. By default, the global scsimgr attribute

hwp_alias_enable is set to true (1). If this attribute is set to false (0), current hardware path aliases

do not change, but new objects are not assigned hardware path aliases when they register. When

the system is rebooted with hwp_alias_enable set to false, no default hardware path aliases are

assigned (they are NULL unless hwp_abs_alias or hwp_comp_alias values are saved).

To disable the default scheme, follow these steps:

1. Enter the following command:

# scsimgr save_attr –a hwp_alias_enable=0

2. Reboot the system.

To enable the default scheme, follow these steps:

1. Enter the following command:

# scsimgr save_attr –a hwp_alias_enable=1

2. Reboot the system.

In addition to storage objects registering during the boot process, default hardware path aliases

(described previously) are assigned when new storage objects are introduced to the system during an

ioscan. However, the following actions that might update the hardware path aliases are not

implemented when ioscan runs:

• lunpath objects that were removed with rmsf and are subsequently rediscovered

• objects that have an instance number changed

• setting the tport_alias or LUN alias attributes

• enabling or disabling the hwp_alias_enable attribute

To automatically assign hardware path aliases for the previous actions, reboot the system.

Setting hardware path aliases manually

If the default hardware path aliasing scheme is not sufficient, you can manually set hardware path

aliases for storage objects with the hwp_abs_alias and hwp_comp_alias scsimgr attributes,

regardless of the hwp_alias_enable attribute setting. If hwp_alias_enable is set to true (1), the

manually assigned hardware path aliases must fit into the default scheme. However, you can