Provided by: amanda-common_2.6.1p1-2_i386 bug

NAME

       amanda-changers - Configuring and Using Amanda Changers

DESCRIPTION

       Amanda uses changers to arbitrate access to devices (amanda-devices(7))
       and data volumes. Changers provide an abstraction of tape robots, but
       are used to manage non-tape media, too. Amanda communicates with
       changers through the Changer API. This manpage contains a user-level
       overview of the API, and does not address details that are only of
       concern to developers. For that purpose, consult the Amanda source code
       and http://wiki.zmanda.com.

TRANSITION

       The Amanda Changer API is in transition from version 1.0 - driven by
       shell scripts invoked for each changer operation - to version 2.0,
       composed of perl objects that can manage parallel access to multiple
       devices and other complexity. When this transition is complete, Amanda
       devices will, in general, be specified via a changer, which will
       provide the necessary device specifier to access a requested volume. In
       the interim, support for the "new" changer syntax is limited to the
       experimental amvault(8).

SPECIFYING CHANGERS

       Changer specifications are strings like chg-disk:/my/vtapes. The chg-
       prefix serves to differentiate changers from devices (see amanda-
       devices(7)). The next portion (disk, in this case) identifies the
       particular changer driver to use, and everything that follows the : is
       interpreted by the driver.

       A name which does not match this pattern, but which matches an old
       changer script (e.g., chg-zd-mtx), invokes the backward-compatibility
       changer driver as chg-compat:chg-zd-mtx. If the name does not match an
       old changer, then it is treated as an Amanda device, and is wrapped by
       the single-device changer, e.g., chg-single:tape:/dev/rmt/0.

       Changers which require additional parameters can also be described in
       amanda.conf(5) with "changer" sections, for example,

       define changer hp-robot {
           tapedev "chg-robot:/dev/sg1"
           property "drives" "0=/dev/nst0;1=/dev/nst0"
           property "slots" "1-10"
       }
       (note that "chg-robot" is not yet implemented, so this is
       hypothetical). A changer defininition creates a changer "alias", in
       this case named hp-robot, which can then be named where an application
       expects a changer - for example, the target of the amvault command.

CHANGER DRIVERS

       This section lists the changer drivers included with Amanda, and basic
       instructions for using them. For complete How-To information, consult
       the Amanda wiki at http://wiki.zmanda.com.

   chg-disk (new)
       tpchanger "chg-disk:/u01/vtapes"

       This changer driver replaces the old chg-disk, supporting parallel
       access to vtapes stored in directories named slotN in the directory
       specified after chg-disk:. It does so by creating numbered "drives" so
       that simultaneous processes can access distinct slots.

   chg-disk (old)
       tapedev "file:/u01/vtapes"
       tpchanger "chg-disk"

       This changer script supports sequential access to vtapes stored in
       directories named slotN in the directory specified by the tapedev
       parameter.

   chg-multi
       tpchanger "chg-multi"
       changerfile "chg-multi-state"

       This script simply round-robins a number of distinct device names, as
       specified in its configuration file. It is useful when all volumes for
       a configuration have different device names -- for example, with S3
       devices. The changerfile need not exist; it is used as a prefix for
       filenames of state files.

   chg-manual
       tpchanger "chg-manual"
       changerfile "chg-manual.conf"

       This script simply provides distinct device names in a round-robin
       fashion, as specified in its configuration file. It is useful when all
       volumes for a configuration have different device names -- for example,
       with S3 devices. The configuration file parameters are (as listed in
       the script):

       resend_mail=900       # resend mail every __ seconds
       timeout_mail=604800   # time out after this many seconds (default 7 days)
       request="[type]"      # How to request a new tape (default "tty_email")
         request="tty"       # Use the tty to ask the user to change tape.
                             # Can´t be use by cron
         request="email"     # Send an email to ask the user to change tape.
         request="tty_email" # Use the tty if it exist or send an email.

   chg-zd-mtx
       tpchanger "chg-zd-mtx"
       changerdev "/dev/sg0"         # used with ´mtx -f´
       changerfile "chg-zd-mtx.conf"
       tapedev "tape:/dev/nst0"

       This script interfaces with a tape drive using the Zubkoff/Dandelion
       version of mtx. That´s the version that takes a device specifier with
       the -f option and has subcommands like status. The configuration file
       parameters are (as listed in the script itself):

       firstslot=?                 #### First storage slot (element)
       lastslot=?                  #### Last storage slot (element)
       cleanslot=-1                #### Slot with cleaner tape -- default is "-1"
                                   #### Set negative to indicate no cleaner available
       driveslot=0                 #### Drive slot number.  Defaults to 0
                                   #### Use the ´Data Transfer Element´ you want
       autoclean=0                 #### Set to ´1´ or greater to enable
       autocleancount=99           #### Number of access before a clean.
       havereader=0                #### If you have a barcode reader, set to 1.
       offline_before_unload=0     #### Does your robot require an
                                   #### ´mt offline´ before mtx unload?
       poll_drive_ready=NN         #### Time (seconds) between tests to see if
                                   #### the tape drive has gone ready (default: 3).
       max_drive_wait=NN           #### Maximum time (seconds) to wait for the
                                   #### tape drive to become ready (default: 120).
       initial_poll_delay=NN       #### initial delay after load before polling for
                                   #### readiness
       slotinfofile=FILENAME       #### record slot information to this file, in
                                   #### the line-based format "SLOT LABEL\n"

   chg-rait
       tpchanger "chg-rait"
       changerfile "chg-rait.conf"

       This changer script constructs RAIT devices out of the devices provided
       by several "sub-changers". The configuration file specifies nchangers,
       the number of subchangers, and then provides tpchanger, changerdev_N,
       changerfile_N, and tpchanger_N for each sub-changer, 1 through N.

   chg-null
       tpchanger "chg-null"

       This changer always provides the device "null:". It is sometimes useful
       in conjunction with chg-rait.

   Unmaintained Changers
       Amanda has many other changer scripts and programs beyond those
       described here (see the changer-src/ in the source directory), but most
       of these scripts are unmaintained and undocumented, and will be removed
       when the new changer API is fully implemented.

SEE ALSO

       amanda(8), amanda.conf(5), amanda-devices(7),

AUTHOR

       Dustin J. Mitchell <dustin@zmanda.com>
           Zmanda, Inc. (http://www.zmanda.com)