1 .\" mtx.1 Document copyright 2000 Eric Lee Green
2 .\" Program Copyright 1996, 1997 Leonard Zubkoff
3 .\" Copyright 2007-2008 by Robert Nelson <robertn@the-nelsons.org>
4 .\" Extensive changes 2000 by Eric Lee Green <eric@badtux.org>
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7 .\" modify it under the terms of the GNU General Public License as
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28 mtx \- control SCSI media changer devices
30 mtx [-f <scsi-generic-device>] [nobarcode] [invert] [noattach] command [ command ... ]
34 command controls single or multi-drive SCSI media changers such as
35 tape changers, autoloaders, tape libraries, or optical media jukeboxes.
36 It can also be used with media changers that use the 'ATTACHED' API,
37 presuming that they properly report the MChanger bit as required
38 by the SCSI T-10 SMC specification.
40 The first argument, given following
42 , is the SCSI generic device corresponding to your media changer.
43 Consult your operating system's documentation for more information (for
44 example, under Linux these are generally /dev/sg0 through /dev/sg15,
45 under FreeBSD these are /dev/pass0 through /dev/passX,
46 under SunOS it may be a file under /dev/rdsk).
48 The 'invert' option will invert (flip) the media (for optical jukeboxes that
49 allow such) before inserting it into the drive or returning it to the
52 The 'noattach' option forces the regular media changer API even if the
53 media changer incorrectly reported that it uses the 'ATTACHED' API.
55 The 'nobarcode' option forces the loader to not request barcodes even if
56 the loader is capable of reporting them.
58 Following these options there may follow
59 one or more robotics control
60 commands. Note that the 'invert' and 'noattach'
61 options apply to ALL of robotics control
67 Report the mtx version number (e.g. mtx 1.2.8) and exit.
71 Report the product type (Medium Changer, Tape Drive, etc.), Vendor ID,
72 Product ID, Revision, and whether this uses the Attached Changer API
73 (some tape drives use this rather than reporting a Medium Changer on a
74 separate LUN or SCSI address).
77 Make further commands use the regular media changer API rather than the
78 _ATTACHED API, no matter what the "Attached" bit said in the Inquiry info.
79 Needed with some brain-dead changers that report Attached bit but don't respond
83 Makes the robot arm go and check what elements are in the slots. This
84 is needed for a few libraries like the Breece Hill ones that do not
85 automatically check the tape inventory at system startup.
88 Reports how many drives and storage elements are contained in the
89 device. For each drive, reports whether it has media loaded in it, and
90 if so, from which storage slot the media originated. For each storage
91 slot, reports whether it is empty or full, and if the media changer
92 has a bar code, MIC reader, or some other way of uniquely identifying
93 media without loading it into a drive, this reports the volume tag
94 and/or alternate volume tag for each piece of media.
95 For historical reasons drives are numbered from 0 and storage slots are
98 .B load <slotnum> [ <drivenum> ]
99 Load media from slot <slotnum> into drive <drivenum>. Drive 0 is assumed
100 if the drive number is omitted.
102 .B unload [<slotnum>] [ <drivenum> ]
103 Unloads media from drive <drivenum> into slot <slotnum>. If <drivenum> is
104 omitted, defaults to drive 0 (as do all commands).
105 If <slotnum> is omitted, defaults to the slot
106 that the drive was loaded from. Note that there's currently no way to
107 say 'unload drive 1's media to the slot it came from', other than to
108 explicitly use that slot number as the destination.
110 .B [eepos <operation>] transfer <slotnum> <slotnum>
111 Transfers media from one slot to another, assuming that your mechanism is
112 capable of doing so. Usually used to move media to/from an import/export
113 port. 'eepos' is used to extend/retract the import/export
114 tray on certain mid-range to high end tape libraries (if, e.g., the tray was
115 slot 32, you might say say 'eepos 1 transfer 32 32' to extend the tray).
116 Valid values for eepos <operation>
117 are 0 (do nothing to the import/export tray), 1, and 2 (what 1 and 2 do varies
118 depending upon the library, consult your library's SCSI-level
121 .B [eepos <operation>] [invert] [invert2] exchange <slotnum> <slotnum> [<slotnum>]
122 Move medium from the first slot to the second slot, placing the medium
123 currently in the second slot either back into the first slot or into the
127 .B first [<drivenum>]
128 Loads drive <drivenum> from the first slot in the media
129 changer. Unloads the drive if there is already media in it (note: you
130 may need to eject the tape using your OS's tape control commands
131 first). Note that this command may not be what you want on large
132 tape libraries -- e.g. on Exabyte 220, the first slot is usually a
133 cleaning tape. If <drivenum> is omitted, defaults to first drive.
137 Loads drive <drivenum> from the last slot in the media changer. Unloads
138 the drive if there is already a tape in it. (Note: you may need to eject
139 the tape using your OS's tape control commands first).
142 Unloads the drive and loads the next tape in sequence. If the drive was
143 empty, loads the first tape into the drive.
145 .B position <slotnum>
146 Positions the robot at a specific slot. Needed by some changers to
147 move to and open the import/export, or mailbox, slot.
150 The original 'mtx' program was written by Leonard Zubkoff and extensively
151 revised for large multi-drive libraries with bar code readers
152 by Eric Lee Green <eric@badtux.org>. See 'mtx.c' for other contributors.
153 .SH BUGS AND LIMITATIONS
155 You may need to do a 'mt offline' on the tape drive to eject the tape
156 before you can issue the 'mtx unload' command. The Exabyte EZ-17 and 220
157 in particular will happily sit there snapping the robot arm's claws around
158 thin air trying to grab a tape that's not there.
160 For some Linux distributions, you may need to re-compile the kernel to
161 scan SCSI LUN's in order to detect the media changer. Check /proc/scsi/scsi
162 to see what's going on.
164 If you try to unload a tape to its 'source' slot, and said slot is
165 full, it will instead put the tape into the first empty
166 slot. Unfortunately the list of empty slots is not updated between
167 commands on the command line, so if you try to unload another drive to
168 a full 'source' slot during the same invocation of 'mtx', it will try
169 to unload to the same (no longer empty) slot and will urp with a SCSI
173 This program reads the Mode Sense Element Address Assignment Page
174 (SCSI) and requests data on all available elements. For larger
175 libraries (more than a couple dozen elements)
176 this sets a big Allocation_Size in the SCSI command block for the
177 REQUEST_ELEMENT_STATUS command in order to be able to read the entire
178 result of a big tape library. Some operating systems may not be able
179 to handle this. Versions of Linux earlier than 2.2.6, in particular,
180 may fail this request due to inability to find contiguous pages of
181 memory for the SCSI transfer (later versions of Linux 'sg' device do
182 scatter-gather so that this should no longer be a problem).
186 command remains in effect for all further commands on a command
187 line. Thus you might want to follow
188 .B eepos 1 transfer 32 32
192 the next command (which clears the
196 Need a better name for 'eepos' command! ('eepos' is the name of the bit
197 field in the actual low-level SCSI command, and has nothing to do with what
201 This program has only been tested on Linux with a limited number of
202 tape loaders (a dual-drive Exabyte 220 tape library, with bar-code
203 reader and 21 slots, an Exabyte EZ-17 7-slot autoloader, and a Seagate
204 DDS-4 autochanger with 6 slots). It may not work on other operating systems
205 with larger libraries,
206 due to the big SCSI request size.
207 Please see the projecdt page http://sourceforge.net/projects/mtx for information
208 on reporting bugs, requesting features and the mailing list for peer support.
211 .B cat /proc/scsi/scsi
212 will tell you what SCSI devices you have.
213 You can then refer to them as
216 etc. by the order they
220 .B camcontrol devlist
221 will tell you what SCSI devices you
222 have, along with which
224 device controls them.
226 Under Solaris, set up your 'sgen' driver so that it'll look for
227 tape changers (see /kernel/drv/sgen.conf and the sgen man page), type
228 .B touch /reconfigure
229 then reboot. You can find your changer in /devices by typing
230 .B /usr/sbin/devfsadm -C
231 to clean out no-longer-extant entries in your /devices directory, then
232 .B find /devices -name \e\(**changer -print
233 to find the device name. Set the symbolic link
236 to that device name (if it is not doing so already).
238 With BRU, set your mount and unmount commands as described on the BRU
239 web site at http://www.bru.com to move to the next tape when backing up
240 or restoring. With GNU
244 for an example of how to use
248 to make multi-tape backups.
253 is currently being maintained by Robert Nelson <robertnelson@users.sourceforge.net> .
254 The 'mtx' home page is http://mtx.sourceforge.net and the actual code is currently available
255 there and via SVN from http://sourceforge.net/projects/mtx.
257 .BR mt (1), loaderinfo (1), tapeinfo (1), scsitape (1), scsieject (1)