HP StoreEver High Availability Path Failover Windows Driver Release Notes Version 1.0.6.3 (5697-3325, June 2014)

In multi-host environments, device discovery on a newly introduced or rebooted
host could be problematic if the library is not idle during the discovery.
Symptom: A host in a multi-initiator environment does not discover a path to the library controller when
it is booted or the devices are rescanned when another initiator is using the library. Some applications
create an exclusive connection to the tape library and prevent drivers from performing proper discovery
and binding. Note that this is not unique to the HP APF drivers and can occur in environments not
using the APF drivers as well.
Workaround: Reboot or rescan devices while the library is not being used.
A failure of the active control path drive and activation of the passive control
path drive near the same time that a reservation is being released may result in
the reservation not being released correctly.
Symptom: Tape library access commands fail with "Reservation Conflict" errors or "Medium Removal
Prevented" errors. In rare cases where access to all paths on the active control path drive is lost at the
same time that a reservation or prevent media removal setting is in the process of being changed or
if all paths are lost to an active control path drive in a multi-initiator environment and one host does
not recover from the path failure it is possible to have a reservation or prevention setting that is no
longer associated with a host. Note that this is not unique to the APF driver and is most likely to occur
in traditional multi-path configurations.
Workaround: Both the ESL G3 library font panel and the Windows diagnostic application provide a
method for clearing the stale settings. In the Windows diagnostic application it is found under
Actions→Clear Nexus Settings.
If the Windows diagnostic application or ESL G3 GUI is not available, most settings can be cleared
by using the library GUI to power-cycle the tape drive hosting the library controller. Persistent reservation
settings must be cleared using the application that established the settings.
Prerequisites
The following are required before installing advanced path failover:
• Host computer with a supported operating system. See “Operating systems ” (page 3).
• Q-series or E-Series HBA
• Dual SAN Fibre Channel fabric configuration
• Compatible library and drive firmware. For minimum firmware requirements, see “Compatibility”
(page 3).
See the SAN Design Guidelines and EBS Compatibility Matrix, which contains supported HBAs and
ISV applications, on the HP Enterprise Backup Solutions (EBS) website for additional information.
http://www.hp.com/go/ebs
Installation instructions
See the HP StoreEver Tape Libraries Failover User Guide for installation instructions.
Related information
For additional information, see these HP web sites:
• http://www.hp.com
• http://www.hp.com/go/storage
• http://www.hp.com/service_locator
• http://www.hp.com/support/manuals
Prerequisites 5