Device names to use with supported device drivers for IBM Tivoli Storage Manager server and storage agent on Windows

Answer

Device Drivers:

On Windows, three device drivers are supported by the Tivoli Storage Manager server and storage
agent.

1. Tivoli Storage Manager device driver

The Tivoli Storage Manager device driver is a kernel driver that supports non-IBM devices or IBM devices that are not supported by the IBM device driver. For a list of supported devices, see IBM Tivoli Storage Manager Supported Devices for AIX HPUX SUN WIN.

2. IBM device driver

The device driver provided by IBM for IBM devices such as LTO and 3592.

3. Window native device driver

Device driver provided by the operating system or the vendor for the device.

Which device driver to use:

The general guidelines are:

1. Always use the IBM device driver for IBM devices that are supported by the driver for all versions of Tivoli Storage Manager server and storage agent.

2. For Tivoli Storage Manager versions prior to 6.2, use the Tivoli Storage Manager device driver for devices that are supported by the driver.

3. Starting with Tivoli Storage Manager server and storage agent version 6.2, we recommend that you use the Windows native device driver, if one is available, for devices that are supported by the Tivoli Storage Manager device driver. Otherwise, you can use the Tivoli Storage Manager device driver.

The following table summarizes the guidelines:

	Tivoli Storage Manager server and storage agent version 6.1 and older	Tivoli Storage Manager server and storage agent version 6.2 and later
IBM devices supported by the IBM device driver	IBM device driver	IBM device driver
Devices supported by the Tivoli Storage Manager device driver	Tivoli Storage Manager device driver	Windows native device driver if one is available. Otherwise, Tivoli Storage manager device driver.

Device Name Formats:

There are two device name formats for devices that are used with Tivoli Storage Manager for Windows: the Windows device name format and the Tivoli Storage Manager device name format.

The Windows device name format is tapeX for a tape drive and changerX for a medium changer where X is the device number. For example, tape0 or changer0.

The Tivoli Storage Manager device name format is mtX.Y.Z.N for a tape drive, opX.Y.Z.N for an optical drive, and lbX.Y.Z.N for a medium changer where

X
indicates the SCSI ID for the device
Y
indicates the logical unit number (LUN) for the device
Z
indicates the bus number supported by the adapter for the device
N
indicates the port number for the SCSI adapter for the device


Device Names:

On Windows, each tape device has a device name that is given by the device driver that controls the device. It also has a device alias name that is in the Tivoli Storage Manager device name format. The following table shows the device name and the device alias name for each device type.

	Device Name	Device Alias Name
IBM tape drives controlled by the IBM device driver	tapeX	mtX.Y.Z.N
IBM medium changers controlled by the IBM device driver	changerX	lbX.Y.Z.N
Non-IBM tape drives controlled by the Tivoli Storage Manager device driver	mtX.Y.Z.N	mtX.Y.Z.N
Non-IBM medium changers controlled by the Tivoli Storage Manager device driver	lbX.Y.Z.N	lbX.Y.Z.N
Optical drives controlled by the Tivoli Storage Manager device driver	opX.Y.Z.N	opX.Y.Z.N
Non-IBM tape drives controlled by the Windows native device driver (Allowed with Tivoli Storage Manager V6.2 and later.)	tapeX	mtX.Y.Z.N
Non-IBM medium changers controlled by the Windows native device driver (Allowed with Tivoli Storage Manager V6.2 and later.)	changerX	lbX.Y.Z.N
Optical drives controlled by the Windows disk driver (Tivoli Storage Manager V6.2 and later)	physicaldriveX	opX.Y.Z.N

Which device name to use:

In general, both the device name and device alias name can be used for the DEVICE parameter in the DEFINE/UPDATE PATH command. However, there are times when one is preferred over the other.

When SANDISCOVERY is enabled, either device name can be specified in the DEFINE/UPDATE PATH command. However, when the device name has changed, SANDISCOVERY will discover a new device name and update the path with the new device name and not the device alias name.

When SANDISCOVERY is disabled, use the device alias names because sometimes when the system is rebooted, the device name might change. However, if the device location has not changed, the device alias name stays the same.

For example, the device name might change from tape0 to tape1, but the device alias name is still mt1.0.0.2 since the device location has not changed. In this case, Tivoli Storage Manager looks at the registry entry for the device at port 2, bus 0, lun 0, and target 1 and finds that the device name is now tape1. The Tivoli Storage Manager administrator does not have to update path to change the device name from tape0 to tape1. However, if the device name is used instead of the device alias name, the path will have to be updated to point to tape1 instead of tape0.


Note:
The information on this technote applies to devices that are supported by the Tivoli Storage Manager
server and storage agent only.