Defines configuration parameters for tape drives on a Tape Coordinator machine
Description
The TapeConfig file includes configuration information about all of the Tape Coordinators running on a Tape Coordinator machine. A TapeConfig file
must reside in the directory named dcelocal/var/dfs/backup on each Tape Coordinator machine.
The TapeConfig file must contain a single line specifying information about each tape drive and its associated Tape Coordinator. It must contain a line for each tape drive whose Tape Coordinator is to be started with the butc command. Otherwise, the butc process cannot start the Tape Coordinator for the drive.
The TapeConfig file is an ASCII file. Each line specifies the following parameters for a tape drive:
Tape size
The Tape Coordinator uses this capacity whenever a tape is used in the drive.
The unit of measurement to be applied to the tape size can be specified as k or K (for kilobytes), m or M (for megabytes), or g or G (for gigabytes); do not leave a space between the number and letter used as a unit identifier. The default unit is kilobytes. You should use a number 10 to 15% lower than the actual tape capacity for the tape size.
End-of-file (EOF) mark size
The Backup System appends an EOF mark of this size after each fileset dump on a tape. The size of the mark can affect the amount of space available
for backup data.
The EOF mark size can vary from 2 kilobytes to 2 megabytes, depending on the type of tape drive used. Use the same abbreviations used for tape capacity to specify the unit of measurement for the EOF mark size. The default unit is bytes (not kilobytes, as for tape capacity). You should increase the file mark size by 10 to 15% to allow for tape variations.
If you do not know the EOF mark size for a tape drive, use the fms command to determine the EOF size. This command produces screen output and an FMSLog file listing the tape capacity and EOF mark size for the drive.
Device name
The name of the tape drive. The format of this name varies with each operating system.
Tape Coordinator ID (TCID)
The identifier of the Tape Coordinator associated with the drive.
Legal values are the integers 0 through 1023. The Backup System can track a maximum of 1024 tape drives; a single machine can house any number of drives.
TCIDs can be specified in any order; it is not necessary to assign them sequentially. Because the bak commands that require you to specify a TCID always use a default TCID of 0 (zero), assign a TCID of 0 (zero) to the Tape Coordinator for the drive you will use most often.
Because it is an ASCII file, the TapeConfig file can be created or modified with a text editor. Creating the file requires write and execute permissions on the dcelocal/var/dfs/backup directory. Editing the file requires write permission on the file. Be precise when editing the file; a tape drive will be inaccessible if its line in the TapeConfig file is specified incorrectly.
Examples
An example of a TapeConfig file for a Tape Coordinator machine follows. The file configures three tape drives on a machine. The first drive, whose device
name is /dev/rmth0h, has a tape size of 1 gigabyte and an EOF mark size of 4 kilobytes; its associated Tape Coordinator has a TCID of 0. The second two drives, /dev/rmth3h and
/dev/rmth4h, each have tape sizes of 2 gigabytes and EOF mark sizes of 1 megabyte; the TCIDs of their respective Tape Coordinators are 3 and 2.
1G 4K /dev/rmth0h 0
2g 1M /dev/rmth3h 3
2G 1m /dev/rmth4h 2
Related Information
Commands: butc(8dfs)
Files: FMSLog(4dfs)