Russ Allbery e3dfba8e6c man-page-conversion-20051208
This is the initial conversion of the AFS Adminstrators Reference into POD
for use as man pages.  The man pages are now generated via pod2man from
regen.sh so that only those working from CVS have to have pod2man
available.  The Makefile only installs.  The pages have also been sorted
out into pod1, pod5, and pod8 directories, making conversion to the right
section of man page easier without maintaining a separate list and allowing
for names to be duplicated between pod5 and pod1 or pod8 (which will likely
be needed in a few cases).

This reconversion is done with a new script based on work by Chas Williams.
In some cases, the output is worse than the previous POD pages, but this is
a more comprehensive conversion.

This is only the first step, and this initial conversion has various
problems.  In addition, the file man pages that didn't have simple names
have not been converted in this pass and will be added later.  Some of the
man pages have syntax problems and all of them have formatting errors.  The
next editing pass, coming shortly, will clean up most of the remaining
mess.
2005-12-08 12:14:33 +00:00

148 lines
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Plaintext

=head1 NAME
fms - Determine a tape's capacity and a tape device's filemark size
=head1 SYNOPSIS
B<fms -tape> <I<tape special file>> [-help]
B<fms -t> <I<tape special file>> [-h]
=head1 DESCRIPTION
The fms command determines the capacity of the tape currently in
the tape device identified by the B<-tape> argument, along with the
size of the filemark for the device. The filemark is also referred to
as the device's end-of-file (EOF) marker, and can differ for each
combination of tape and tape device.
As the Tape Coordinator writes a dump, it writes a filemark between the
data included from each volume and also tracks the amount of space left before
the end of the tape (EOT). For some tape devices, the filemark is large
enough (multiple megabytes) that failure to consider it leads the Tape
Coordinator significantly to overestimate the available space.
The intended use of this command is to determine tape capacity and filemark
size values that can be specified in a tape device's entry in the
B</usr/afs/backup/tapeconfig> file. For certain types of tape
drives, the Tape Coordinator operates more efficiently when the
B<tapeconfig> file lists accurate values. For further
discussion, see the I<IBM AFS Administration Guide> chapter on
configuring the Backup System.
Insert a tape in the drive before issuing this command.
=head1 CAVEATS
Do not use this command on compressing tape devices in compression mode or
with tape devices that handle tapes of multigigabyte (or multiterabyte)
capacity. It does not produce accurate results in those cases.
For alternate suggestions on the values to record in the B<tapeconfig>
file for compressing drives, see the I<IBM AFS Administration Guide>
chapter on configuring the Backup System.
Running the command completely overwrites the tape, so use a blank one or
one that can be recycled.
Because it writes filemarks to the complete length of the tape, the command
can take from several hours to more than a day to complete.
=head1 OPTIONS
=over 4
=item -tape
Specifies the UNIX device name of the tape device for which to determine
filemark size and the capacity of the tape it currently contains. The
format varies on different system types, but usually begins with
B</dev>; an example is B</dev/sd0a>.
=item -help
Prints the online help for this command. All other valid options
are ignored.
=back
=head1 OUTPUT
The command generates output both on the standard output stream and in the
B<fms.log> file that it creates in the current working
directory. The output reports the capacity of the tape in the device
and the device's filemark size.
The first few lines of output 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 both screen and file output provide the following
information:
=over 4
=item *
C<Tape capacity is> I<number> C<bytes>:
specifies the size, in bytes, of the tape in the device.
=item *
C<File marks are> I<number> C<bytes>:
specifies the device's filemark size in bytes.
=back
The following message indicates that the fms command interpreter
cannot access the tape device. The command halts.
Can't open tape drive I<device>
The following message indicates that the command interpreter cannot create
the B<fms.log> log file. Again, the command
halts.
Can't open log file
=head1 EXAMPLES
The following command illustrates the output for the device called
B</dev/rmt1h>:
% fms /dev/rmt1h
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 1910205 bytes
The following appears in the fms.log file:
fms test started
wrote 9230 blocks
Finished file mark test
Tape capacity is 151224320 bytes
File marks are 2375680 bytes
=head1 PRIVILEGE REQUIRED
The issuer must be able to insert and write to files in the currently
working directory, if the B<fms.log> file does not already
exist. If it already exists, the issuer need only be able to write to
it.
=head1 SEE ALSO
L<fms.log(1)>,
L<tapeconfig(1)>
=head1 COPYRIGHT
IBM Corporation 2000. <http://www.ibm.com/> All Rights Reserved.
This documentation is covered by the IBM Public License Version 1.0. It was
converted from HTML to POD by software written by Chas Williams and Russ
Allbery, based on work by Alf Wachsmann and Elizabeth Cassell.