=head1 NAME

vos_clone - Creates a shared-space copy of a volume on a partition

=head1 SYNOPSIS

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B<vos clone> S<<< [B<-id>] <I<volume name or ID>> >>>
    S<<< [B<-server>] <I<server name>> >>>
    S<<< [B<-partition>] <I<partition name>> >>>
    S<<< [B<-toname> <I<volume name on destination>>] >>>
    S<<< [B<-toid> <I<volume ID on destination>>] >>> [B<-offline>] [B<-readonly>]
    S<<< [B<-cell> <I<cell name>>] >>> [B<-noauth>]
    [B<-localauth>] [B<-verbose>] [B<-encrypt>] [B<-help>]

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=head1 DESCRIPTION

The B<vos clone> command creates a copy-on-write copy of a volume on the
same partition and server ass the parent volume.

A clone is a copy of a volume that does only stores the changes from the
parent volume. Cloning is a primitive operation that is used by the B<vos
move>, B<vos backup>, and B<vos release> commands. A clone functions using
the same mechanism as a backup volume, but it is persistent. Clone volumes
can be used as point-in-time copies of the parent vollume, but they must be
used with care.

=head1 CAUTIONS

This command is not used during normal OpenAFS administration and may
have adverse effects on the VLDB if not used properly! This command
should only be used by an expert.

Deleting or moving the parent volume makes the clone volume inaccessible,
but the clone volume remains in the VLDB and on disk, and it needs to be
cleaned up manually.

There is a maximum limitation of 7 clones when using the namei
fileserver. You may safely create up to 4 clones using the B<vos clone>
command. The other three clone slots are used by the backup volume, a
read-only replica and the temporary clone that is created when executing a
B<vos move>, B<vos dump>, or other B<vos> commands.

Some commands do not work properly on clone volumes. B<vos move> is one
such command.

Currently, the maximum size of a volume is 2 terabytes (2^31 bytes).

=head1 OPTIONS

=over 4

=item [B<-id>] <I<volume name or ID>>

Specifies either the complete name or volume ID number of a read/write
volume.

=item [B<-server>] <I<machine name>>

Identifies the file server machine where the source volume resides. Provide
the machine's IP address or its host name (either fully qualified or using
an unambiguous abbreviation). For details, see L<vos(1)>.

=item [B<-partition>] <I<partition name>>

Names the partition where the source volume resides. Provide the full
partition name (for, example, B</vicepa>) or one of the abbreviated forms
described in L<vos(1)>.

=item B<-toname> <I<volume name for new copy>>

The complete name of the new volume to create.

=item B<-toid> <I<volume id for new copy>>

The complete id of the new volume to create.

=item B<-offline>

Leaves the new volume flagged as off-line in the volume database.

=item B<-readonly>

Flags the new volume as read-only in the volume database.

=item B<-cell> <I<cell name>>

Names the cell in which to run the command. Do not combine this argument
with the B<-localauth> flag. For more details, see L<vos(1)>.

=item B<-noauth>

Assigns the unprivileged identity C<anonymous> to the issuer. Do not
combine this flag with the B<-localauth> flag. For more details, see
L<vos(1)>.

=item B<-localauth>

Constructs a server ticket using a key from the local
F</usr/afs/etc/KeyFile> file. The B<vos> command interpreter presents
it to the Volume Server and Volume Location Server during mutual
authentication. Do not combine this flag with the B<-cell> argument or
B<-noauth> flag. For more details, see L<vos(1)>.

=item B<-verbose>

Produces on the standard output stream a detailed trace of the command's
execution. If this argument is omitted, only warnings and error messages
appear.

=item B<-encrypt>

Encrypts the command so that the operation's results are not transmitted
across the network in clear text.

=item B<-help>

Prints the online help for this command. All other valid options are
ignored.

=back

=head1 OUTPUT

This command has no output unless C<-verbose> is specified or there is
an error.

=head1 PRIVILEGE REQUIRED

The issuer must be listed in the F</usr/afs/etc/UserList> file on the
machines specified with the B<-toserver> and B<-fromserver> arguments and
on each database server machine.  If the B<-localauth> flag is included,
the issuer must instead be logged on to a server machine as the local
superuser C<root>.

=head1 SEE ALSO

L<vos(1)>,
L<vos_backup(1)>,
L<vos_copy(1)>,
L<vos_move(1)>,
L<vos_shadow(1)>

=head1 COPYRIGHT

Copyright 2008 Jason Edgecombe <jason@rampaginggeek.com>

This documentation is covered by the BSD License as written in the
doc/LICENSE file. This man page was written by Jason Edgecombe for
OpenAFS.
