1AMANDA-CHANGERS(7) Miscellanea AMANDA-CHANGERS(7)
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6 amanda-changers - Configuring and Using Amanda Changers
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9 Amanda uses changers to arbitrate access to devices (amanda-devices(7))
10 and data volumes. Changers provide an abstraction of tape robots, but
11 are used to manage non-tape media, too. Amanda communicates with
12 changers through the Changer API. This manpage contains a user-level
13 overview of the API, and does not address details that are only of
14 concern to developers. For that purpose, consult the Amanda source code
15 and http://wiki.zmanda.com.
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18 The Amanda Changer API is in transition from version 1.0 - driven by
19 shell scripts invoked for each changer operation - to version 2.0,
20 composed of perl objects that can manage parallel access to multiple
21 devices and other complexity. When this transition is complete, Amanda
22 devices will, in general, be specified via a changer, which will
23 provide the necessary device specifier to access a requested volume. In
24 the interim, support for the "new" changer syntax is limited to the
25 experimental amvault(8).
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28 Changer specifications are strings like chg-disk:/my/vtapes. The chg-
29 prefix serves to differentiate changers from devices (see amanda-
30 devices(7)). The next portion (disk, in this case) identifies the
31 particular changer driver to use, and everything that follows the : is
32 interpreted by the driver.
33 A name which does not match this pattern, but which matches an old
35 changer script (e.g., chg-zd-mtx), invokes the backward-compatibility
36 changer driver as chg-compat:chg-zd-mtx. If the name does not match an
37 old changer, then it is treated as an Amanda device, and is wrapped by
38 the single-device changer, e.g., chg-single:tape:/dev/rmt/0.
39 Changers which require additional parameters can also be described in
41 amanda.conf(5) with "changer" sections, for example,
42 define changer hp-robot {
44 tapedev "chg-robot:/dev/sg1"
45 property "drives" "0=/dev/nst0;1=/dev/nst0"
46 property "slots" "1-10"
47 }
48 (note that "chg-robot" is not yet implemented, so this is
49 hypothetical). A changer defininition creates a changer "alias", in
50 this case named hp-robot, which can then be named where an application
51 expects a changer - for example, the target of the amvault command.
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54 This section lists the changer drivers included with Amanda, and basic
55 instructions for using them. For complete How-To information, consult
56 the Amanda wiki at http://wiki.zmanda.com.
57 chg-disk (new)
59 tpchanger "chg-disk:/u01/vtapes"
60 This changer driver replaces the old chg-disk, supporting parallel
62 access to vtapes stored in directories named slotN in the directory
63 specified after chg-disk:. It does so by creating numbered "drives" so
64 that simultaneous processes can access distinct slots.
65 chg-disk (old)
67 tapedev "file:/u01/vtapes"
68 tpchanger "chg-disk"
69 This changer script supports sequential access to vtapes stored in
71 directories named slotN in the directory specified by the tapedev
72 parameter.
73 chg-multi
75 tpchanger "chg-multi"
76 changerfile "chg-multi-state"
77 This script simply round-robins a number of distinct device names, as
79 specified in its configuration file. It is useful when all volumes for
80 a configuration have different device names -- for example, with S3
81 devices. The changerfile need not exist; it is used as a prefix for
82 filenames of state files.
83 chg-manual
85 tpchanger "chg-manual"
86 changerfile "chg-manual.conf"
87 This script simply provides distinct device names in a round-robin
89 fashion, as specified in its configuration file. It is useful when all
90 volumes for a configuration have different device names -- for example,
91 with S3 devices. The configuration file parameters are (as listed in
92 the script):
93 resend_mail=900 # resend mail every __ seconds
95 timeout_mail=604800 # time out after this many seconds (default 7 days)
96 request="[type]" # How to request a new tape (default "tty_email")
97 request="tty" # Use the tty to ask the user to change tape.
98 # Can´t be use by cron
99 request="email" # Send an email to ask the user to change tape.
100 request="tty_email" # Use the tty if it exist or send an email.
101 chg-zd-mtx
103 tpchanger "chg-zd-mtx"
104 changerdev "/dev/sg0" # used with ´mtx -f´
105 changerfile "chg-zd-mtx.conf"
106 tapedev "tape:/dev/nst0"
107 This script interfaces with a tape drive using the Zubkoff/Dandelion
109 version of mtx. That´s the version that takes a device specifier with
110 the -f option and has subcommands like status. The configuration file
111 parameters are (as listed in the script itself):
112 firstslot=? #### First storage slot (element)
114 lastslot=? #### Last storage slot (element)
115 cleanslot=-1 #### Slot with cleaner tape -- default is "-1"
116 #### Set negative to indicate no cleaner available
117 driveslot=0 #### Drive slot number. Defaults to 0
118 #### Use the ´Data Transfer Element´ you want
119 autoclean=0 #### Set to ´1´ or greater to enable
120 autocleancount=99 #### Number of access before a clean.
121 havereader=0 #### If you have a barcode reader, set to 1.
122 offline_before_unload=0 #### Does your robot require an
123 #### ´mt offline´ before mtx unload?
124 poll_drive_ready=NN #### Time (seconds) between tests to see if
125 #### the tape drive has gone ready (default: 3).
126 max_drive_wait=NN #### Maximum time (seconds) to wait for the
127 #### tape drive to become ready (default: 120).
128 initial_poll_delay=NN #### initial delay after load before polling for
129 #### readiness
130 slotinfofile=FILENAME #### record slot information to this file, in
131 #### the line-based format "SLOT LABEL\n"
132 chg-rait
134 tpchanger "chg-rait"
135 changerfile "chg-rait.conf"
136 This changer script constructs RAIT devices out of the devices provided
138 by several "sub-changers". The configuration file specifies nchangers,
139 the number of subchangers, and then provides tpchanger, changerdev_N,
140 changerfile_N, and tpchanger_N for each sub-changer, 1 through N.
141 chg-null
143 tpchanger "chg-null"
144 This changer always provides the device "null:". It is sometimes useful
146 in conjunction with chg-rait.
147 Unmaintained Changers
149 Amanda has many other changer scripts and programs beyond those
150 described here (see the changer-src/ in the source directory), but most
151 of these scripts are unmaintained and undocumented, and will be removed
152 when the new changer API is fully implemented.
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155 amanda(8), amanda.conf(5), amanda-devices(7),
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158 Dustin J. Mitchell <dustin@zmanda.com>
159 Zmanda, Inc. (http://www.zmanda.com)
160Amanda 2.6.1p2 11/05/2009 AMANDA-CHANGERS(7)