Determines tape size and end of file (EOF) mark size for a tape drive
Synopsis
fms -device device_name [-help]
Options
-device device_name
Names the device name of the tape drive whose tape size and EOF mark size are to be reported. The format of this name varies with each operating
system.
-help
Prints the online help for this command. All other valid options specified with this option are ignored.
The help and apropos commands available with all command suites are also available with the fms command. See the bos help and bos apropos reference pages for examples using these commands.
Description
The fms command is used with the Backup System to determine the tape size and EOF mark size for the tape drive indicated with -device. It is
primarily useful for determining information required for specifying a tape drive's parameters in the TapeConfig file. It can also be used to initialize a tape because it inserts file marks
onto the entire tape. The Backup System, therefore, does not have to insert the file marks when it dumps information to the tape. (File marks are inserted after each fileset dumped to tape.) The
binary file for the fms command resides in dceshared/bin/fms.
Before issuing the command, insert a tape into the drive. Use a blank tape, one that can be recycled, or one to be initialized with file marks. The tape is overwritten while the command executes. Because this command inserts file marks onto the entire tape, it can take from several hours to more than a day to complete.
The command sends output to both the terminal and an FMSLog file that it creates in the directory it is to be issued from. The output reports the tape size and EOF mark size for the tape drive. It is recommended that the tape size returned by the command be reduced by 10 to 15 percent before being used in the TapeConfig file. It is also recommended that the EOF mark size be increased by 10 to 15 percent before being used in the TapeConfig file.
Privilege Required
Each time it is run, the fms command creates the FMSLog file if it does not already exist in the directory the command is issued from. In
this case, the issuer of the command must have write, execute, and insert permissions on the current working directory. If the file already exists, the command truncates the file (clears its
contents) before writing to it, in which case the issuer needs only write permission on the file.
Output
The fms command produces terminal output and an FMSLog file in the directory from which it is issued. The terminal output and FMSLog file list
the tape capacity and the size of the EOF mark for the tape drive specified by -device.
The first few lines of output displayed on the screen and written to the FMSLog file include status information about the execution of the command, including such information as the number of blocks and the number of file marks written to the tape by the command. The last two lines of terminal and file output provide the following information:
Tape capacity is number bytes
Specifies the tape size, in bytes, for the tape drive.
File marks are number bytes
Specifies the file mark size, in bytes, for the tape drive.
If a problem with the tape drive prevents execution of the command, no FMSLog file is created and the message Can't open tape device device_name is displayed. If a problem prevents creation of the FMSLog file, the message Can't open log file is displayed. In both cases, execution of the command stops when the message is displayed.
Examples
The following command determines the EOF mark size for the tape drive whose device name is /dev/rmt1h:
$ fms /dev/rmt1h
The command displays the following output on the screen:
wrote block: 130408
Finished data capacity test - rewinding
wrote 1109 blocks, 1109 file marks
Finished file mark test
Tape capacity is 2136604672 bytes
File marks are 1910220 bytes
It writes the following information to the FMSLog file:
fms test started
wrote 130408 blocks
Tape capacity is 2136604672 bytes
File marks are 1910220 bytes
The tape drive used in the example uses tapes 2,136,604,672 bytes in size, and creates end of file marks of size 1,910,220 bytes in size.
Related Information
Files: FMSLog(4dfs)