Control Path Failover

The Control Path Failover (CPF) feature of the IBM medium changer device drivers provides a mechanism whereby commands sent to a failing control path on a medium changer may fail over to a working control path. On Windows 2000 and Windows Server 2003, this support requires two kernel-level device drivers to be running on the system, in addition to the medium changer driver ibmcgxx.sys (the “base” driver). If CPF support is not provided, the base driver will be adequate to operate the changer.

One of the two additional drivers required to enable CPF support is a filter driver that will be installed automatically if the magchgrf.inf (rather than the magchgr.inf) file is used for the base driver install. Depending on the version of the driver you have, you may see either or both these inf files when unzipping. The other additional driver is a virtual software bus, called the Changer Bus Enumerator, which must be installed using ibmcgbs.inf. The Changer Bus Enumerator must be installed before the base driver and filter driver installation. Because it is a virtual bus, no hardware will be plugged in and Windows will not recognize the presence of new hardware by the standard plug-and-play protocols.

V6.0.8.2 and later of the IBM medium changer driver support Control Path Failover (CPF).

Major architectural changes were made to the driver to include this support, and these changes are in effect regardless of whether your environment includes support for the CPF feature. A new procedure for installing the driver has been introduced. In particular, the changer driver on any given platform requires installation of three .sys files with their corresponding .inf files:

 ibmcgbsxx.sys (installed by ibmcgbs.inf)

 ibmcgxx.sys and ibmcgftxx.sys (installed by magchgrf.inf) ('xx' in the file names refers to either 2k or 2k3.)

Instructions on how to install ibmcgbsxx.sys are included in the document CPF_install.doc.

Installation of the other two .sys files follows the instructions for Windows 200x in the IBM Ultrium Device Drivers Installation and User’s Guide, GA32-0430.

In order to reduce complexity, the file install.exe is included in the driver package to perform the steps in CPF_install.doc automatically. However, at the time of writing, this install.exe has the following limitations:

 It may not work correctly on Windows running on Intel Itanium®.

 It may require a reboot. Please follow the prompts on your screen.

 It must not be run from the command line or from a network share. Please copy the entire driver package to a LOCAL directory and double click the install.exe icon to run.

If you are installing lower than V6.0.8.2, or one of the previously listed limitations applies to your installation, the CPF_install.doc instructions are included in 3.4.2, “CPF driver

installation using the CPF_install.doc” on page 107.

3.4.1 CPF driver installation using install.exe

1. To run install.exe, open Device Manager to verify that Windows has discovered all library devices on your system (Figure 3-40). The medium changer may show as the library type or as “Unknown Medium Changer”. If the tape drives are not listed under Tape Drives, they may be listed in Other Devices.

Figure 3-40 Device manager with library installed

2. If the devices do not display, then attempt a manual rescan by selecting Action → Scan for Hardware Changes (Figure 3-41 on page 105).

Note: We recommend that you check the latest version of the readme file for any changes to the installation process.

Figure 3-41 Hardware scan

3. Once Windows has discovered the tape libraries, double-click install.exe in the directory where the driver file was unzipped (see Figure 3-42).

Figure 3-42 install.exe in driver install directory

4. You may see a screen during installation indicating Windows cannot verify the software has not been modified since it was published (Figure 3-43 on page 106). Click Yes and continue.

Figure 3-43 Changer Bus Enumerator installation warning

5. If you are installing a driver that has not been certified by the Microsoft Windows Hardware Quality Laboratories (WHQL), you will be see a warning screen (see Figure 3-44). To continue installing the driver, click Continue Anyway.

Figure 3-44 Driver installation certification warning

6. At the end of the installation process, a message box indicates the installation is complete.

Subject to the limitations previously listed, the virtual and actual hardware are installed correctly on your system.

To continue with the library installation process, see either 3.2, “Installing IBM tape device drivers for Windows 2000” on page 82 or 3.3, “Installing IBM tape device drivers for Windows 2003” on page 91.

Note: All drivers released by IBM have been through a complete test to ensure that they are stable and conform to specified requirements.

3.4.2 CPF driver installation using the CPF_install.doc

The Control Path Failover (CPF) feature of the IBM medium changer device drivers provides a mechanism whereby commands sent to a failing control path on a medium changer may fail over to a working control path. On Windows 2000 and Windows Server 2003, this support requires two kernel-level device drivers to be running on the system, in addition to the medium changer driver ibmcgxx.sys (the “base” driver). If CPF support is not provided, the base driver will be adequate to operate the changer.

One of the two additional drivers required to enable CPF support is a filter driver that will be installed automatically if the magchgrf.inf (rather than the magchgr.inf) file is used for the base driver install. Depending on the version of the driver you have, you may see either or both these inf files when unzipping. The other additional driver is a virtual software bus, called the Changer Bus Enumerator, which must be installed using ibmcgbs.inf. The Changer Bus Enumerator must be installed prior to the base driver and filter driver installation. Because it is a virtual bus, no hardware will be plugged in and Windows will not recognize the presence of new hardware by the standard plug-and-play protocols. The Control Panel's Add/Remove Hardware feature will be used to instruct the system to recognize the virtual hardware. This documentation outlines the procedure required to install the Changer Bus Enumerator.

Please note that minor differences may exist between the screen shots below and the windows displayed by the wizard on your system. Unless otherwise specified, the

documentation is based on the look and feel of Windows Server 2003. This is similar enough to Windows 2000 to eliminate confusion.

These instructions assume that you have obtained a copy of the IBM Tape Device Driver (IBMTape.W32_6xxx.zip or IBMTape.W64_6xxx.zip) with CPF support and have unzipped it into the c:\driver_install directory. Any directory on your system will work, but you need to specify this directory when the system prompts for driver location.

1. If there is an IBM medium changer device driver already installed on your system, you must uninstall it. Right-click My Computer, select Manage, and go to Device Manager.

Under the subheading Medium Changers, right-click each device and select Uninstall.

Follow the prompts to uninstall the device. Under the subheading System devices, if there is an entry called Changer Bus Enumerator, right-click the entry and uninstall it also. Then run the utility uninst.exe from the driver install package and reboot your system.

2. From the Control Panel, double-click Add/Remove Hardware (Windows 2000) or Add Hardware (Windows Server 2003). This starts the Add Hardware Wizard (Figure 3-45 on page 108). Click Next.

Note: If you have driver V6.0.8.2 or later, you may use the instructions in 3.4.1, “CPF driver installation using install.exe” on page 104.

Figure 3-45 Welcome window

3. If running Windows 2000, Figure 3-46 prompts you to add/troubleshoot a device or uninstall/unplug a device. Select Add/Troubleshoot a Device and click Next.

Figure 3-46 Add/Remove window

4. Windows now searches for new plug-and-play hardware, as in Figure 3-47 on page 109.

Within a few seconds, you are prompted if you have connected the hardware. Select Yes, I have already connected the hardware and click Next (Figure 3-48 on page 109).

Figure 3-47 Searching Wizard window

Figure 3-48 Is hardware connected window

5. A list of installed hardware appears. Select Add a new hardware device and click Next