AFS-Command

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#
# $Id: VOS.pod,v 7.2 2004/05/11 15:55:17 wpm Exp $
#
# (c) 2003-2004 Morgan Stanley and Co.
# See ..../src/LICENSE for terms of distribution.
#

=head1 NAME

AFS::Command::VOS - OO API to the AFS vos command

=head1 SYNOPSIS

    use AFS::Command::VOS;

    my $vos = AFS::Command::VOS->new();

    my $vos = AFS::Command::VOS->new
      (
       command			=> $path_to_your_vos_binary,
      );

    my $vos = AFS::Command::VOS->new
      (
       localauth			=> 1,
       encrypt			=> 1,
      );

=head1 DESCRIPTION

This module implements an OO API wrapper around the AFS 'vos' command.
The supported methods depend on the version of the vos binary used,
and are determined automagically.

=head1 METHODS -- Inherited

All of the following methods are inherited from the AFS::Command::Base
class.  See that documentation for details.

=over

=item new

=item errors

=item supportsOperation

=item supportsArgument

=back

=head1 METHODS (dump, restore)

Both the 'dump' and 'restore' methods are special, since this API
supports compression to and from the filesystem when dumping or
restoring the volume.  Normally, "vos dump -file" will just wrote the
uncompressed volume dump to the file, but this API can compress it.
This is a huge cost savings in disk space, assuming you can afford the
CPU time to perform the compression (this is the 21st century -- you
probably can).

Both of these commands return simply boolean true/false values, but
they have some special case handling for the -file argument, and
support several special arguments that are extensions implemented in
this API only.

=head2 dump

The vos help string is:

    vos dump: dump a volume
    Usage: vos dump -id <volume name or ID> [-time <dump from time>] [-file <dump file>]
		    [-server <server>] [-partition <partition>] [-cell <cell name>]
		    [-noauth] [-localauth] [-verbose] [-encrypt]

The corresponding method invocation looks like:

    my $result = $vos->dump
      (
       # Required arguments
       id			=> $id,
       file			=> $file, # SPECIAL CASE!!! (see below)
       # Optional arguments
       time			=> $time,
       server			=> $server,
       partition		=> $partition,
       cell                     => $cell,
       noauth                   => 1,
       localauth                => 1,
       verbose                  => 1,
       encrypt                  => 1,
       # Enhanced arguments
       gzip			=> $gzip,
       bzip2			=> $bzip2,
       filterout		=> [ @command ], # OR [ [ @cmd1 ], [ @cmd2 ], ... ]
      );

The first thing to notice is that 'file' is optional to the vos dump
command itself, but required in this API.  The second thing to notice
is the addition of three new arguments: gzip, bzip2 and filterout.

=over

=item file

This argument specifies the file to which the vos dump output should
be written.  If this file ends in '.gz' or '.bz2', then gzip or bzip2
will be used to compress the output before it is written to the
filesystem.  This is accomplished using a pipe, so there is no
intermediate file written to disk first.

By default, 'vos dump' will write the volume dump to stdout, which is
not what you want in most applications.  If you really want the volume
to be written to stdout, then you have to explicitly say so:

   my $result = $vos->dump
     (
      ...
      file			=> 'stdout',
      ...
     );

=item gzip, bzip2

Both of these arguments will turn on compression explicitly, and if
the file specified doesn't end in the appropriate extension already
('.gz' for gzip, and '.bz2' for bzip2), then the extension is appended
to the filename.

The value of these arguments specifies the degree of compression used,
an should be a single numeric digit, from 0 to 9.  See the gzip and
bzip2 man pages for more information.

These arguments are also mutually exclusive.

=item filterout

This is an advanced feature, and one that allows the volume dump to be
filtered through any arbitrary number of commands before it is
compressed (optionally) and written to the filesystem.  The value of
this argument is either an ARRAY reference to a list of command line
arguments, suitable for passing to exec(), or an ARRAY or such ARRAYS,
when more than one filter command is being used.

For example, the author has a requirement to pass all volume dumps
through a simple filter called 'newversion', which reads a volume
dump, changes the directory version numbers to the current utime
value, and writes the volume dump to stdout.  Trust me, you really
don't want to know why.

    my $result = $vos->dump
      (
       ...
       filterout		=> [ 'newversion' ],
       ...
      );

If there were command line arguments for this command, then they must
be given as follows:

    my $result = $vos->dump
      (
       ...
       filterout		=> [ 'newversion', '-arg1', '-value1' ],
       ...
      );

These args are passed directly to exec, with no shell involved.  When
more than one command is given, then an ARRAY or ARRAYs must be
specified as follows:

    my $result = $vos->dump
      (
       ...
       filterout		=> [
                                    [ 'command1', '-arg1', '-value1' ],
                                    [ 'command2', '-arg2', '-value2' ],
                                    [ 'command3', '-arg3', '-value3' ],
                                   ],
       ...
      );

If B<ANY> of the filterout commands exits with a non-zero status, then
the entire dump method invocation is considered to fail.  You may or
may not get a valid volume dump file, compressed or otherwise,
depending on the behavior of the commands you specify.

=back

=head2 restore

The vos help string is:

    vos restore: restore a volume
    Usage: vos restore -server <machine name> -partition <partition name>
		       -name <name of volume to be restored> [-file <dump file>]
		       [-id <volume ID>] [-overwrite <abort | full | incremental>]
		       [-offline] [-readonly]
                       [-creation <dump | keep | new>] [-lastupdate <dump | keep | new>]
                       [-cell <cell name>] [-noauth]
		       [-localauth] [-verbose] [-encrypt]
    Where: -offline    leave restored volume offline
	   -readonly   make restored volume read-only

The corresponding method invocation looks like:

    my $result = $vos->restore
      (
       # Required arguments
       server			=> $server,
       partition		=> $partition,
       name			=> $name,
       file			=> $file, # SPECIAL CASE!!! (see below)
       # Optional arguments
       id			=> $id,
       overwrite		=> 'abort' | 'full' | 'incremental',
       offline			=> 1,
       readonly			=> 1,
       creation			=> 'dump' | 'keep' | 'new',
       lastupdate		=> 'dump' | 'keep' | 'new',
       cell                     => $cell,
       noauth                   => 1,
       localauth                => 1,
       verbose                  => 1,
       encrypt                  => 1,
       # Enhanced arguments
       gunzip			=> 1,
       bunzip2			=> 1,
       filterin			=> [ @command ], # OR [ [ @cmd1 ], [ @cmd2 ], ... ]
      );

NOTE: The 'creation' and 'lastupdate' options are available only in a
very recent patch to the vos command, which should be available in the
OpenAFS 1.2.11 or 1.2.12 releases.  These options control how the
Creation and LastUpdate timestamps are set on the restored volume.

The 3 values these options can take, and their meanings, are:

=over

=item dump

Use the timestamp from the volume dump file being restored to the
volume.  This is the default behavior for the LastUpdate timestamp.

=item keep

Preserve the existing timestamp on the volume.

=item new

Set the timestamp to the current time.  This is the default behavior
for the Creation timestamp.

=back

Note that the default behavior creates the condition where the
Creation time is newer than the LastUpdate time, and when this is
true, "vos examine" (or any command that display the timestamps in the
volume header, really) will show the Creation time as the LastUpdate
time, presumably because it would be confusing to show the volume as
having been updated before it was created.

Similar to 'vos dump', the 'file' argument is optional to 'vos
restore', but required in this API.  There are also three new
arguments: gunzip, bunzip2, and filterin.  The analogy with 'vos dump'
is by design entirely symmetrical.

=over

=item file

This argument specifies the file from which the vos restore input
should be read.  If the file ends in '.gz' or '.bz2', then gunzip or
bunzip2 will be used to uncompress the input before it is read by vos
restore.  This is accomplished using a pipe, so there is no
intermediate file written to disk first.

By default, 'vos restore' will read the volume dump from stdin, which
is not what you want in most applications.  If you really want the
volume to be read from stdin, then you have to explicitly say so:

   my $result = $vos->restore
     (
      ...
      file			=> 'stdin',
      ...
     );

=item gunzip, bunzip2

Both of these arguments will turn on uncompression explicitly,
although they only need to be specified if the need for uncompression
can not be determined dynamically from the filename.  If the files are
compressed, but lack the proper extension ('.gz' or '.bz2'), or if the
compressed input is being read from stdin, then uncompression must be
specified explicitly.

These arguments have boolean values, since uncompression is either on
or off.  They are mutually exclusive as well.

=item filterin

This is an advanced feature, and one that allows the volume dump to be
filtered through any arbitrary number of commands after it is
uncompressed (optionally) and read by vos restore.  The value of this
argument is either an ARRAY reference to a list of command line
arguments, suitable for passing to exec(), or an ARRAY or such ARRAYS,
when more than one filter command is being used.

Lacking a better example, let's assume the author's 'newversion'
utility is being applied to the restore process, rather than the dump.

    my $result = $vos->restore
      (
       ...
       filterin			=> [ 'newversion' ],
       ...
      );

If there were command line arguments for this command, then they must
be given as follows:

    my $result = $vos->restore
      (
       ...
       filterin			=> [ 'newversion', '-arg1', '-value1' ],
       ...
      );

These args are passed directly to exec, with no shell involved.  When
more than one command is given, then an ARRAY or ARRAYs must be
specified as follows:

    my $result = $vos->restore
      (
       ...
       filterin			=> [
                                    [ 'command1', '-arg1', '-value1' ],
                                    [ 'command2', '-arg2', '-value2' ],
                                    [ 'command3', '-arg3', '-value3' ],
                                   ],
       ...
      );

If B<ANY> of the filterin commands exits with a non-zero status, then
the entire restore method invocation is considered to fail.  You may
or may not get a valid volume restored to your fileserver, depending
on the behavior of the commands you specify.

=back

=head1 METHODS (with complex return values)

=head2 examine

=over

=item Arguments

The vos help string is:

    vos examine: everything about the volume
    Usage: vos examine -id <volume name or ID> [-extended] [-cell <cell name>]
                       [-noauth] [-localauth] [-verbose] [-encrypt]
    Where: -extended   list extended volume fields

The corresponding method invocation looks like:

    my $result = $vos->examine
      (
       # Required arguments
       id			=> $id,
       # Optional arguments
       cell			=> $cell,
       extended			=> 1,
       noauth			=> 1,
       localauth		=> 1,
       verbose			=> 1,
       encrypt			=> 1,
      );

=item Return Values

This method returns an AFS::Object::Volume object, which in
turn contains one or more AFS::Object::VolumeHeader objects,
as well as an AFS::Object::VLDBEntry, which contains one or
more AFS::Object::VLDBSite objects.

    my $result = $vos->examine
      (
       id			=> $volname,
       cell			=> $cell,
      ) || die $vos->errors();

    foreach my $header ( $result->getVolumeHeaders() ) {
	my ($server,$partition) = ($header->server(),$header->partition());
	print "[header] server = $server, partition = $partition\n";
    }

    my $vldbentry = $result->getVLDBEntry();

    foreach my $vldbsite ( $vldbentry->getVLDBSites() ) {
	my ($server,$partition) = ($vldbsite->server(),$vldbsite->partition());
	print "[vldbsite] server = $server, partition = $partition\n";
    }

Each of these objects has the following attributes and methods:

B<AFS::Object::Volume>

This object is nothing more than a container for the VolumeHeader and
VLDBEntry objects, and has no attributes of its own.  It has two
methods for extracting the objects it contains.

    Methods			Returns
    -------			-------
    getVLDBEntry()		a single AFS::Object::VLDBEntry object
    getVolumeHeaders()		list of AFS:Command::Result::VolumeHeader objects

B<AFS::Object::VLDBEntry>

This object is created by parsing this stanza of output:

    root.afs
	RWrite: 536918445     ROnly: 536918450
	number of sites -> 6
	   server pasafq3 partition /vicepc RW Site
	   server pasafq3 partition /vicepc RO Site
	   server pasafq1 partition /viceph RO Site
	   server pasafq2 partition /vicepg RO Site
	   server pasafq4 partition /vicepc RO Site
	   server pasafq5 partition /vicepg RO Site

The object attributes are taken from the first two lines of output:

    root.afs
	RWrite: 536918445     ROnly: 536918450

The following attributes should always be present:

    Attributes			Values
    ----------			------
    name			Volume name
    rwrite			Numeric Volume ID for the RW volume
    locked			Boolean value, indicating the VLDB entry is locked or not

The following attributes may be present, if there are volumes of the
associated type in the VLDB entry:

    Attributes			Values
    ----------			------
    ronly			Numeric Volume ID for the RO volume
    backup			Numeric Volume ID for the BK volume
    rclone			Numeric Volume ID for the RClone volume, if present

Note that the 'rclone' attribute is only present if the volume was
actively being cloned while being examined.  This is true when a 'vos
release' command is actively updating the RO volumes.

The following methods are available:

    Methods			Returns
    -------			-------
    getVLDBSites()		list of AFS::Object::VLDBSite objects

B<AFS::Object::VLDBSite>

This object is created by parsing the individual VLDB sites in the
VLDB entry, namely the lines such as:

	   server pasafq5 partition /vicepg RO Site

The following attributes are always available:

    Attributes			Values
    ----------			------
    server			Fileserver hostname
    partition			Fileserver /vice partition name
    type			"RO" | "RW" | "BK"
    status			Site status.

Note that the status is the field indicating the state of the volume
during a 'vos release' command, and this will be an empty string for
VLDB entries which are completely in sync.

B<AFS::Object::VolumeHeader>

This object is created by parsing the volume header stanza, such as:

    root.afs                          536908042 RW         23 K  Off-line
        npiafa3 /viceph
        RWrite  536908042 ROnly  536908046 Backup          0
        MaxQuota          0 K
        Creation    Sat Sep 23 03:41:50 2006
        Copy        Fri Aug 31 01:12:21 2007
        Backup      Fri Oct 17 20:59:02 2003
        Last Update Sat Nov  7 15:12:40 1998
        0 accesses in the past day (i.e., vnode references)

Note that there may very well be more than one of these, if a
.readonly is examined, since the volume headers for all of the RO
volumes will be queried.

The attributes available in this object depend on the method
arguments, as well as the state of the volume (less information can be
obtained when a volume is busy, for example).

The following attributes should always be present.

    Attributes			Values
    ----------			------
    id				Numeric Volume ID
    status			online | offline | busy
    attached			Boolean

The 'attached' attribute is a Boolean that indicates whether or not
the volume is attached by the volserver.  A volume which can not be
brought online due to volume header problems will be offline, and
unattached (attached == 0), but a volume can be offline for other
reasons, (eg. vos offline, or more than one volume with the same ID on
the same server), and still be attached (attached == 1).

The following attributes are present only if the volume's status is
'online':

    Attributes			Values
    ----------			------
    name			Volume Name
    type			"RO" | "RW" | "BK"
    size			Numeric size in KB
    server			Fileserver hostname
    partition			Fileserver /vice partition
    maxquota			Volume quota in KB
    creation			Volume creation date (ctime format, eg: Sat Oct  6 04:39:50 2001)
    copyTime			Volume copy date   (also in ctime format)
    backupTime			Volume backup date (also in ctime format)
    access      Volume Last Access date (also in ctime format)
    update			Volume update date (also in ctime format)
    accesses			Number of volume accesses since the last reset
    rwrite			Numeric Volume ID for the RW volume
    ronly			Numeric Volume ID for the RO volume
    backup			Numeric Volume ID for the BK volume
    rclone			Numeric Volume ID for the RClone volume, if present

Note that the 'rclone' attribute is only present if the volume was
actively being cloned while being examined.  This is true when a 'vos
release' command is actively updating the RO volumes.

The following attributes are only present if the 'extended' argument
was specified (see below for details on access the raw and author
stats):

    Attributes			Values
    ----------			------
    files			Number of files in the volume
    raw				Generic AFS::Object object
    author			Generic AFS::Object object

The 'raw' and 'author' stats are implemented as a hierarchy of simple,
generic AFS::Object objects, which have nothing but a couple
of attributes, and no special methods associated with them.

The 'raw' object has the following attributes:

    Attributes			Values
    ----------			------
    reads			Generic AFS::Object object
    writes			Generic AFS::Object object

Both of the 'reads' and 'writes' objects have the following
attributes:

    Attributes			Values
    ----------			------
    same			Generic AFS::Object object
    diff			Generic AFS::Object object

Both of the 'same' and 'diff' objects have the following attributes:

    Attributes			Values
    ----------			------
    total			Numeric value
    auth			Numeric value

The 'author' object has the following attributes:

    Attributes			Values
    ----------			------
    0sec			Generic AFS::Object object
    1min			Generic AFS::Object object
    10min			Generic AFS::Object object
    1hr				Generic AFS::Object object
    1day			Generic AFS::Object object
    1wk				Generic AFS::Object object

Each of the above interval value objects has the following attributes:

    Attributes			Values
    ----------			------
    file			Generic AFS::Object object
    dir				Generic AFS::Object object

Both the 'file' and 'dir' objects have the following attributes:

    Attributes			Values
    ----------			------
    same			Numeric value

lib/AFS/Command/VOS.pod  view on Meta::CPAN

    Attributes			Values
    ----------			------
    partition			Fileserver /vice partition name

When used to encapsulate 'vos listpart' output, this object has no
relevant methods.  Note, however, that this version of the API reuses
this object to represent other partition-related data (see 'vos
listvol' method documentation, for example), but they are not relevant
in this usage of the object.  This multiple personality of the objects
may be changed in a future release, so don't get too attached to the
specific class names.

See the AFS::Object documentation for a discussion of the
planned evolution of the API.

=back

=head2 listvldb

=over

=item Arguments

The vos help string is:

    vos listvldb: list volumes in the VLDB
    Usage: vos listvldb [-name <volume name or ID>] [-server <machine name>]
			[-partition <partition name>] [-locked] [-quiet] [-nosort]
			[-cell <cell name>] [-noauth] [-localauth] [-verbose] [-encrypt] 
    Where: -locked     locked volumes only
	   -quiet      generate minimal information
	   -nosort     do not alphabetically sort the volume names

The corresponding method invocation looks like:

    my $result = $vos->listvldb
      (
       # Optional arguments
       name			=> $name,
       server			=> $server,
       partition		=> $partition,
       locked			=> 1,
       quiet			=> 1,
       nosort			=> 1,
       cell                     => $cell,
       noauth                   => 1,
       localauth                => 1,
       verbose                  => 1,
       encrypt                  => 1,
      );

=item Return Values

This method returns an AFS::Object::VLDB object, which has a
few attributes, and contains one or more
AFS::Object::VLDBEntry objects, which in turn contain
AFS::Object::VLDBSite objects, as well as their own
attributes.

NOTE: the VLDBEntry and VLDBSite objects are the same as those used by
the 'examine' method, since that command also queries the VLDB for
part of its return values.  See that discussion above for some
relevant details on the parsing of those objects, which will no be
repeated here.

    my $result = $vos->listvldb
      (
       cell				=> $cell,
      ) || die $vos->errors();

    print("VLDB contains " . $result->total() " volumes, " .
	  $result->locked() . " of which are locked\n");

    foreach my $entry ( $result->getVLDBEntries() ) {
	my $name = $entry->name();
	foreach my $attr ( $entry->listAttributes() ) {
	    print "Volume $name has attribute $attr => " . $entry->$attr() . "\n";
	}
	foreach my $site ( $entry->getVLDBSites() ) {
	    my %attrs = $site->getAttributes();
	    while ( my($attr,$value) = each %attrs ) {
		print "Site has attribute $attr => $value\n";
	    }
	}
    }

Another way to slice and dice this data:

    foreach my $name ( $result->getVolumeNames() ) {
	my $entry = $result->getVLDBEntry( name => $name );
	....
    }

Each of these objects has the following attributes and methods:

B<AFS::Object::VLDB>

This object has two attributes, and several methods:

    Attributes			Values
    ----------			------
    total			Number of VLDBEntries in the results
    locked			Number of locked volumes in the results

    Methods			Returns
    -------			-------
    getVolumeNames()		list of volume names in the results
    getVolumeIds()		list of numeric volume IDs
    getVLDBEntry(name => $name)	the AFS::Object::VLDBEntry for name $name
    getVLDBEntry(id => $id)	the AFS::Object::VLDBEntry for id $id
    getVLDBEntries()		list of AFS::Object::VLDBEntry objects
    getVLDBEntryByName($name)   the AFS::Object::VLDBEntry for $name
    getVLDBEntryById($id)   	the AFS::Object::VLDBEntry for $id

NOTE: name to volume mappings are one to one, but id to volume
mappings are many to one, since a single logical VLDB entry can have
several IDs associated with it (RW, RO, BK, and/or RC).

B<AFS::Object::VLDBEntry>

This object also has a few attributes, and a few methods.  The 'name'

lib/AFS/Command/VOS.pod  view on Meta::CPAN

    my $result = $vos->status
      (
       server			=> $server,
      ) || die $vos->errors();
    print "Server has " . $result->transactions() . "active transactions\n";

    foreach my $transaction ( $result->getTransactions() ) {
	print("There are active transactions for volume ID " .
	      $transaction->volume() . "\n");
    }

B<AFS::Object::VolServer>

This object has exactly one attribute, and several methods:

    Attributes				Values
    ----------				------
    transactions			Number of active transactions on the volserver

    Methods				Returns
    -------				-------
    getTransactions			list of AFS::Object::Transaction objects
    getVolumes				list of volume IDs for which there are transactions
    getTransactionByVolume($volume)	a single AFS::Object::Transaction object for the volume $volume

B<AFS::Object::Transaction>

This object has several attributes:

    Attributes				Values
    ----------				------
    transaction				Numeric transaction ID
    created				Creation date (in ctime format)
    attachFlags				String (exact meaning unclear)
    volume				Numeric volume ID
    partition				Vice partition on whcih the volume resides
    procedure				What is being done to the volume
    packetRead				Numeric value
    lastReceiveTime			Time value (utime format)
    packetSend				Numeric value
    lastSendTime			Time value (utime format)

NOTE: These attributes just come from a straight parsing of output like this:

    --------------------------------------
    transaction: 170423  created: Wed Oct  8 15:59:12 2003
    attachFlags:  offline
    volume: 536963097  partition: /vicepf  procedure: Restore
    packetRead: 222  lastReceiveTime: 1065643165  packetSend: 1  lastSendTime: 1065643165
    --------------------------------------

To understand the meaning of these various fields (which to the
author's knowledge are not documented anywhere), see the OpenAFS
source code.  Some of these values are obvious, or intuitive, but
others are not.

=back

=head1 METHODS (with simple return values)

All of the following commands return a simple Boolean (true/false)
value, if they succeed or fail.

=head2 addsite

The vos help string is:

    vos addsite: add a replication site
    Usage: vos addsite -server <machine name for new site> -partition <partition name for new site>
		       -id <volume name or ID> [-cell <cell name>]
		       [-noauth] [-localauth] [-verbose] [-encrypt]

The corresponding method invocation looks like:

    my $result = $vos->addsite
      (
       # Required arguments
       server			=> $server,
       partition		=> $partition,
       id			=> $id,
       # Optional arguments
       cell                     => $cell,
       noauth                   => 1,
       localauth                => 1,
       verbose                  => 1,
       encrypt                  => 1,
      );

=head2 backup

The vos help string is:

    vos backup: make backup of a volume
    Usage: vos backup -id <volume name or ID> [-cell <cell name>]
		      [-noauth] [-localauth] [-verbose] [-encrypt]

The corresponding method invocation looks like:

    my $result = $vos->backup
      (
       # Required arguments
       id			=> $id,
       # Optional arguments
       cell                     => $cell,
       noauth                   => 1,
       localauth                => 1,
       verbose                  => 1,
       encrypt                  => 1,
      );

=head2 backupsys

The vos help string is:

    vos backupsys: en masse backups
    Usage: vos backupsys [-prefix <common prefix on volume(s)>+] [-server <machine name>]
			 [-partition <partition name>] [-exclude]
			 [-xprefix <negative prefix on volume(s)>+] [-dryrun]
			 [-cell <cell name>] [-noauth] [-localauth] [-verbose] [-encrypt]
    Where: -exclude    exclude common prefix volumes
	   -dryrun     no action



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