Planning the update procedure, Online update – HP Brocade 4Gb SAN Switch for HP BladeSystem p-Class User Manual

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Perform empirical testing.
Empirical testing may be required for some devices, to determine whether they bind by PID. 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 procedure in ”

Devices that bind by PID are unable to adapt to the new format, and one of three approaches must be

taken with them:

• A plan can be created for working around the device driver’s limitations in such a way as to allow

an online update. See the Detailed Procedures section for examples of how this could be done.

• The device can be upgraded to drivers that do not bind by PID.

• Downtime can be scheduled to reset the device during the core PID update process, which

generally allows the mapping to be rebuilt.

If either of the first two options are used, the procedures should again be validated in the test

environment.

Determine the behavior of multipathing software, including but not limited to:

• HBA time-out values

• Multipathing software time-out values

• Kernel time-out values

Planning the update procedure

Whether it is best to perform an offline or online update depends on the uptime requirements of the site.

•

An offline update that all devices attached to the fabric be offline.

•

With careful planning, it should be safe to update the core PID format parameter in a live, production

environment. This requires dual fabrics with multipathing software. Avoid running backups during the

update process, as tape drives tend to be very sensitive to I/O interruption. The online update process

is only intended for use only in uptime-critical dual-fabric environments, with multipathing software

(high-uptime environments should always use a redundant fabric SAN architecture). Schedule a time

for the update when the least critical traffic is running.

All switches running any version of Fabric OS 3.1.2 and later or 4.2.0 and later are shipped with the

Core Switch PID Format enabled, so it is not necessary to perform the PID format change on these

switches.

Migrating from manual PID binding (such as persistent binding on an HBA) to manual WWN binding and

upgrading drivers to versions that do not bind by PID can often be done before setting the core PID format.

This reduces the number of variables in the update process.

Online update

The following steps are intended to provide SAN administrators a starting point for creating site-specific

procedures.

Back up all data and verify backups.

Verify that the multipathing software can automatically switchover between fabrics seamlessly. If there

is doubt, use the software’s administrative tools to manually disassociate or mark offline all storage

devices on the first fabric to be updated.