User's Manual

NOTE: The installation requires Windows Installer version 4.5 or later. If it is not present,

the installer reports the following errors:

• Error 0x80070643: Failed to install MSI package

• Error 0x80070643: Failed to execute MSI package.

• Error 0x80070643: Failed to configure per-machine MSI package.

If these errors appear, download the Windows Installer appropriate for your version of

Windows using the following link:

http://www.microsoft.com/en-us/download/details.aspx?id=8483

The installation process creates a directory:

C:\Program Files\Hewlett-Packard\Failover\

3. If the server doesn’t already have the HP StoreEver Tape Drivers for Windows, you can obtain

the driver package from the Driver — Storage Tape page as described in Step 1 and then

run the installer file as Administrator to install the drivers.

Uninstalling drivers

To remove the drivers:

1. Select Start→Programs→Control Panel.

2. Select Advanced Failover Drivers entry, click Uninstall/Change.

3. Follow the provided prompts to complete the driver removal.

Windows driver theory of operation

The advanced path failover drivers support data path failover and control path failover on HP

LTO-6 drives integrated into HP tape libraries.

A failover device driver must identify devices accessible over the different paths available and

associate paths with devices so that it is able to mask duplicate paths and present a single path

to an ISV application.

As devices are discovered by the operating system and the DEVICE OBJECT is passed into the

driver for initialization, the driver determines if the device is a tape or changer device and is a

candidate for failover. If the device is a candidate for failover, the driver determines the serial

number (SN) or worldwide name (WWN) of the device.

If the device is capable of advanced path failover, the driver determines whether failover is enabled

for the device. If the device does support failover and failover is enabled, then the driver will mask

all duplicate paths and present a single path to application clients. If the device does not support

failover, if failover is not enabled, or if an error occurred while attempting to determine the

failover-enabled state, then the driver will not modify the presentation of paths to the device to

applications.

Driver components

Windows advanced path failover drivers consists of two drivers: a storage bus filter driver and an

intermediate class driver. The storage bus filter driver processes OS device notifications (PnP

notifications) to identify available paths to tape and media changer devices capable of supporting

advanced path failover. The intermediate class driver works with the devices that have been

identified as advanced path failover capable devices and manages the active paths to the changer

and tape drives.

This architecture follows the architecture of Microsoft’s MPIO. MPIO only supports disk devices

and cannot be used directly.

Windows driver theory of operation 37