Empirical Testing - HP AA-RS2WC-TE Installation Manual

Technical Specifications
way. Whenever possible, HP recommends using up-to-date drivers that do not
bind by PID, as binding by PID creates management difficulty in a number of
scenarios.
The drivers shipping by default with HP/UX and AIX at the time of this writing
still bind by PID, and so detailed procedures are provided for these operating
systems in the final section of this overview. Similar procedures can be developed
for other operating systems which run HBA drivers that bind by PID. HP
recommends upgrading to WWN-binding drivers if these are available.
There is no inherent PID binding problem with either AIX or HP/UX. It is the
HBA drivers shipping with these operating systems that bind by PID. Both OSs
are expected to release HBA drivers that bind by WWN, and these may already be
available through some support channels. Work with the appropriate support
provider to get more information about driver availability.
Also evaluate whether or not devices which are manually bound by PID can be
migrated to WWN binding. If not, determine what procedures will be required to
change their bindings.
It is also important to understand how multi-pathing software will react when one
of the two fabrics is taken offline. If the time-outs are set correctly, then
switchover between fabrics should be transparent to the users of the system.

Empirical Testing

For some devices, it may not be possible to determine whether or not they bind by
PID by asking the support provider. In these cases, empirical testing is
recommended. If you are not sure about a device, work with the support provider
to create a test environment.
Create as close a match as practical between the test environment and the
production environment, and perform an update using the Online Update
procedure. Devices that bind by PID are unable to adapt to the new format, and
one of three approaches can be taken with them:
188
Create a plan can for working around the device driver's limitations in such a
way as to allow an online update. See the section
page 193 for examples.
Upgrade the device drivers to drivers that do not bind by PID.
Schedule downtime to reset the device during the core PID update process,
which generally allows the mapping to be rebuilt.
Detailed Procedures, on
Core Switch 2/64 V4.1 Installation Guide