Jump to content United States-English
HP.com Home Products and Services Support and Drivers Solutions How to Buy
» Contact HP
HP.com home
HP Tru64 UNIX and TruCluster Server Version 5.1B-4: Patch Summary and Release Notes > Chapter 1 Enhancements, Improvements, and Features

New Attribute Controls Tape Driver Path Control

» 

»Table of Contents
Content starts here

A new cam tape subsystem attribute, enable_preferred_path, lets you control preferred path behavior for a tape driver. Enabling this attribute (1) causes the tape driver to assign different paths to different tape drives. The default (0) disables preferred path behavior. The revised sys_attrs_cam(5) reference page delivered in this kit describes the enable_preferred_path attribute.

A problem may exist when using preferred path behavior when you use a no-rewind tape device. If the application is not expecting the tape to change position between a previous tape close and a subsequent tape open, the data already on the tape may be lost with the next write command, possibly resulting in unusable backups. This problem only occurs when a system has multiple initiators.

The following steps will prevent this problem from occurring:

  • Before performing a backup, reserve the device and lock down the path as follows:

    # mt -f /dev/ntape/tape0 reserve

  • After performing the backup, release the device and unlock the path as follows:

    # mt -f /dev/ntape/tape0 release

Printable version
Privacy statement Using this site means you accept its terms
© 2006 Hewlett-Packard Development Company, L.P.