HP Brocade 4Gb SAN Switch for HP BladeSystem p-Class User Manual

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208 Configuring the PID format

Collect device, software, hardware, and configuration data.
The following is a non-comprehensive list of information to collect:

• HBA driver versions

• Fabric OS versions

• RAID array microcode versions

• SCSI bridge code versions

• JBOD drive firmware versions

• Multipathing software versions

• HBA time-out values

• Multipathing software time-out values

• Kernel time-out values

• Configuration of switch

Make a list of manually configurable PID drivers.
Some device drivers do not automatically bind by PID, but allow the operator to manually create a PID

binding. For example, persistent binding of PIDs to logical drives may be done in many HBA drivers.

Make a list of all devices that are configured this way. If manual PID binding is in use, consider

changing to WWN binding.

The following are some of the device types that may be manually configured to bind by PID:

• HBA drivers (persistent binding)

• RAID arrays (LUN access control)

• SCSI bridges (LUN mapping)

Analyze data.
After you have determined the code versions of each device on the fabric, they must be evaluated to

find out if any automatically bind by PID. It may be easiest to work with the support providers of these

devices to get this information. If this is not possible, you may need to perform empirical testing.

Binding by PID can create management difficulties in a number of scenarios. HP recommends that you

not use drivers that bind by PID. If the current drivers do bind by PID, upgrade to WWN-binding

drivers if possible.

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 this chapter. Similar procedures can

be developed for other operating systems that run HBA drivers that bind by PID.

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 operating systems are expected to release HBA drivers

that bind by WWN, and these drivers may already be available through some support channels.

Work with the appropriate support provider to find out about driver availability.

It is also important to understand how multipathing software reacts when one of the two fabrics is

taken offline. If the time-outs are set correctly, the failover between fabrics should be transparent to the

users.

You should use the multipathing software to manually fail a path before starting maintenance on that

fabric.