1MTX(1) General Commands Manual MTX(1)
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6 mtx - control SCSI media changer devices
7
9 mtx [-f <scsi-generic-device>] [nobarcode] [invert] [noattach] command
10 [ command ... ]
11
13 The mtx command controls single or multi-drive SCSI media changers such
14 as tape changers, autoloaders, tape libraries, or optical media juke‐
15 boxes. It can also be used with media changers that use the 'ATTACHED'
16 API, presuming that they properly report the MChanger bit as required
17 by the SCSI T-10 SMC specification.
18
20 The first argument, given following -f , is the SCSI generic device
21 corresponding to your media changer. Consult your operating system's
22 documentation for more information (for example, under Linux these are
23 generally /dev/sg0 through /dev/sg15, under FreeBSD these are
24 /dev/pass0 through /dev/passX, under SunOS it may be a file under
25 /dev/rdsk).
26 The 'invert' option will invert (flip) the media (for optical jukeboxes
28 that allow such) before inserting it into the drive or returning it to
29 the storage slot.
30 The 'noattach' option forces the regular media changer API even if the
32 media changer incorrectly reported that it uses the 'ATTACHED' API.
33 The 'nobarcode' option forces the loader to not request barcodes even
35 if the loader is capable of reporting them.
36 Following these options there may follow one or more robotics control
38 commands. Note that the 'invert' and 'noattach' options apply to ALL of
39 robotics control commands.
40
43 --version Report the mtx version number (e.g. mtx 1.2.8) and exit.
44 inquiry Report the product type (Medium Changer, Tape Drive, etc.),
47 Vendor ID, Product ID, Revision, and whether this uses the
48 Attached Changer API (some tape drives use this rather than
49 reporting a Medium Changer on a separate LUN or SCSI
50 address).
51 noattach Make further commands use the regular media changer API
53 rather than the _ATTACHED API, no matter what the "Attached"
54 bit said in the Inquiry info. Needed with some brain-dead
55 changers that report Attached bit but don't respond to
56 _ATTACHED API.
57 inventory Makes the robot arm go and check what elements are in the
59 slots. This is needed for a few libraries like the Breece
60 Hill ones that do not automatically check the tape inventory
61 at system startup.
62 status Reports how many drives and storage elements are contained in
64 the device. For each drive, reports whether it has media
65 loaded in it, and if so, from which storage slot the media
66 originated. For each storage slot, reports whether it is
67 empty or full, and if the media changer has a bar code, MIC
68 reader, or some other way of uniquely identifying media with‐
69 out loading it into a drive, this reports the volume tag
70 and/or alternate volume tag for each piece of media. For
71 historical reasons drives are numbered from 0 and storage
72 slots are numbered from 1.
73 load <slotnum> [ <drivenum> ]
75 Load media from slot <slotnum> into drive <drivenum>. Drive 0
76 is assumed if the drive number is omitted.
77 unload [<slotnum>] [ <drivenum> ]
79 Unloads media from drive <drivenum> into slot <slotnum>. If
80 <drivenum> is omitted, defaults to drive 0 (as do all com‐
81 mands). If <slotnum> is omitted, defaults to the slot that
82 the drive was loaded from. Note that there's currently no way
83 to say 'unload drive 1's media to the slot it came from',
84 other than to explicitly use that slot number as the destina‐
85 tion.
86 [eepos <operation>] transfer <slotnum> <slotnum>
88 Transfers media from one slot to another, assuming that your
89 mechanism is capable of doing so. Usually used to move media
90 to/from an import/export port. 'eepos' is used to
91 extend/retract the import/export tray on certain mid-range to
92 high end tape libraries (if, e.g., the tray was slot 32, you
93 might say say 'eepos 1 transfer 32 32' to extend the tray).
94 Valid values for eepos <operation> are 0 (do nothing to the
95 import/export tray), 1, and 2 (what 1 and 2 do varies depend‐
96 ing upon the library, consult your library's SCSI-level docu‐
97 mentation).
98 [eepos <operation>] [invert] [invert2] exchange <slotnum> <slotnum>
100 [<slotnum>]
101 Move medium from the first slot to the second slot, placing
102 the medium currently in the second slot either back into the
103 first slot or into the optional third slot.
104 first [<drivenum>]
107 Loads drive <drivenum> from the first slot in the media
108 changer. Unloads the drive if there is already media in it
109 (note: you may need to eject the tape using your OS's tape
110 control commands first). Note that this command may not be
111 what you want on large tape libraries -- e.g. on Exabyte 220,
112 the first slot is usually a cleaning tape. If <drivenum> is
113 omitted, defaults to first drive.
114 last [<drivenum>]
117 Loads drive <drivenum> from the last slot in the media
118 changer. Unloads the drive if there is already a tape in it.
119 (Note: you may need to eject the tape using your OS's tape
120 control commands first).
121 next [<drivenum>]
123 Unloads the drive and loads the next tape in sequence. If the
124 drive was empty, loads the first tape into the drive.
125 position <slotnum>
127 Positions the robot at a specific slot. Needed by some chang‐
128 ers to move to and open the import/export, or mailbox, slot.
129
132 The original 'mtx' program was written by Leonard Zubkoff and exten‐
133 sively revised for large multi-drive libraries with bar code readers by
134 Eric Lee Green <eric@badtux.org>. See 'mtx.c' for other contributors.
135
137 You may need to do a 'mt offline' on the tape drive to eject the tape
138 before you can issue the 'mtx unload' command. The Exabyte EZ-17 and
139 220 in particular will happily sit there snapping the robot arm's claws
140 around thin air trying to grab a tape that's not there.
141 For some Linux distributions, you may need to re-compile the kernel to
143 scan SCSI LUN's in order to detect the media changer. Check
144 /proc/scsi/scsi to see what's going on.
145 If you try to unload a tape to its 'source' slot, and said slot is
147 full, it will instead put the tape into the first empty slot. Unfortu‐
148 nately the list of empty slots is not updated between commands on the
149 command line, so if you try to unload another drive to a full 'source'
150 slot during the same invocation of 'mtx', it will try to unload to the
151 same (no longer empty) slot and will urp with a SCSI error.
152 This program reads the Mode Sense Element Address Assignment Page
154 (SCSI) and requests data on all available elements. For larger
155 libraries (more than a couple dozen elements) this sets a big Alloca‐
156 tion_Size in the SCSI command block for the REQUEST_ELEMENT_STATUS com‐
157 mand in order to be able to read the entire result of a big tape
158 library. Some operating systems may not be able to handle this. Ver‐
159 sions of Linux earlier than 2.2.6, in particular, may fail this request
160 due to inability to find contiguous pages of memory for the SCSI trans‐
161 fer (later versions of Linux 'sg' device do scatter-gather so that this
162 should no longer be a problem).
163 The eepos command remains in effect for all further commands on a com‐
165 mand line. Thus you might want to follow eepos 1 transfer 32 32 with
166 eepos 0 as the next command (which clears the eepos bits).
167 Need a better name for 'eepos' command! ('eepos' is the name of the bit
169 field in the actual low-level SCSI command, and has nothing to do with
170 what it does).
171 This program has only been tested on Linux with a limited number of
173 tape loaders (a dual-drive Exabyte 220 tape library, with bar-code
174 reader and 21 slots, an Exabyte EZ-17 7-slot autoloader, and a Seagate
175 DDS-4 autochanger with 6 slots). It may not work on other operating
176 systems with larger libraries, due to the big SCSI request size.
177 Please see the projecdt page http://sourceforge.net/projects/mtx for
178 information on reporting bugs, requesting features and the mailing list
179 for peer support.
180
182 Under Linux, cat /proc/scsi/scsi will tell you what SCSI devices you
183 have. You can then refer to them as /dev/sga, /dev/sgb, etc. by the
184 order they are reported.
185 Under FreeBSD, camcontrol devlist will tell you what SCSI devices you
187 have, along with which pass device controls them.
188 Under Solaris, set up your 'sgen' driver so that it'll look for tape
190 changers (see /kernel/drv/sgen.conf and the sgen man page), type touch
191 /reconfigure then reboot. You can find your changer in /devices by typ‐
192 ing /usr/sbin/devfsadm -C to clean out no-longer-extant entries in your
193 /devices directory, then find /devices -name \∗changer -print to find
194 the device name. Set the symbolic link /dev/changer to point to that
195 device name (if it is not doing so already).
196 With BRU, set your mount and unmount commands as described on the BRU
198 web site at http://www.bru.com to move to the next tape when backing up
199 or restoring. With GNU tar, see mtx.doc for an example of how to use
200 tar and mtx to make multi-tape backups.
201
204 This version of mtx is currently being maintained by Robert Nelson
205 <robertnelson@users.sourceforge.net> . The 'mtx' home page is
206 http://mtx.sourceforge.net and the actual code is currently available
207 there and via SVN from http://sourceforge.net/projects/mtx.
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210 mt(1),loaderinfo(1),tapeinfo(1),scsitape(1),scsieject(1)
211 MTX1.3 MTX(1)