Veritas NetBackup™ Device Configuration Guide
- Introducing device configuration
- Section I. Operating systems
- About configuring tape drive device files in AIX
- Creating AIX no rewind device files for tape drives
- About device drivers and files for HP-UX persistent DSFs
- About configuring persistent DSFs
- About HP-UX legacy device drivers and files
- About configuring legacy device files
- Creating legacy SCSI and FCP robotic controls on HP-UX
- About the required Linux SCSI drivers
- About configuring robot and drive control for Linux
- Installing/reinstalling the sg and the st drivers
- About Solaris robotic controls
- About Solaris tape drive device files
- Configuring Solaris SAN clients to recognize FT media servers
- Section II. Robotic storage devices
- Robot overview
- Oracle StorageTek ACSLS robots
- About removing tapes from ACS robots
- Robot inventory operations on ACS robots
- NetBackup robotic control, communication, and logging
- NetBackup robotic control, communication, and logging for UNIX systems
- ACS robotic test utility
- ACS configurations supported
- Device configuration examples
About non-QIC tape drives on AIX
Variable length block and fixed length block refer to how the operating system reads from and writes to a tape. Variable-mode devices allow more flexibility to read previously written tapes. Many tape devices can be accessed in either mode. NetBackup assumes variable length for non-quarter inch cartridge (QIC) drives.
For more information, see the chdev(1) and smit(1) man pages and the system management guide. The smit application is the most convenient way to change from fixed to variable-length-block devices manually.
For NetBackup, you must configure non-QIC tape drives as variable-length-block devices. Otherwise NetBackup can write data but may not be able to read it correctly. During a read, you may see a not in tar format error.
When you add a non-QIC tape drive to NetBackup, NetBackup issues the chdev command to configure the drive as a variable length block device. For reference, the following is the command that NetBackup uses to configure a drive for variable mode:
/usr/sbin/chdev -l Dev -a block_size=0
Dev represents the logical identifier for the drive (for example: rmt0 or rmt1).
Therefore, you do not have to configure the drive manually for variable mode.