HP-UX Mass Storage Stack - Hardware Path Aliasing

# scsimgr save_attr -Cdisk -I1 -a hwp_abs_alias=mpt0

class instance hwpath alias

disk 1 64000/0xfa00/0x0 mpt0

In this scenario where a user-defined alias path is conflicting with the alias created using the default

scheme, the first object to register is assigned the given alias path and the alias of the other object

that is assigned the same hwpath alias is set to NULL.

# scsimgr save_attr -a hwp_alias_enable=default

Value of attribute hwp_alias_enable saved successfully

Then, reboot the system. The ioscan command displays the results:

# ioscan -P alias_path | egrep 'disk|0/0/0/0'

ext_bus 0 0/0/0/0 mpt0

tgtpath 0 0/0/0/0.0x0 mpt0.0x0

lunpath 0 0/0/0/0.0x0.0x0 mpt0.0x0.mpt0

disk 1 64000/0xfa00/0x0 N/A

You can avoid this by choosing the user-defined aliases carefully, and by ensuring that they do not

conflict with an alias created using the default scheme. For example, you can set the alias path to

mpt_disk1 or something similar in the previous scenario so that the alias path is not conflicting with

an alias created with the default scheme.

HBA 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 default hardware path alias is driver instance # with no space between the two. For

example, fcd1. This is an absolute alias because this is the first part of the hardware path that

can be aliased. Virtual HBAs are assigned a component alias (driver instance #). For

example, a virtual HBA hardware path alias is fcd1.fcd10.

Target path objects

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

Note: If this object’s HBA already has an absolute alias value set, a saved hwp_abs_alias

value results in no default hardware path alias for this object (it remains NULL). For more

information, see Setting Hardware Path Aliases Manually

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

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

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

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

hardware path that it assumes to already be aliased. The target port instance number is the

number that is used. If there is no target port associated with the target path, the default hardware

path alias remains NULL.

Lunpath objects

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

Note: If this object’s HBA or target post already has an absolute alias value set, a saved

hwp_abs_alias value results in no default hardware path alias for this object (it remains NULL).

For more information, see Setting hardware path aliases manually

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