1 .\" mtx.1 Document copyright 2000 Eric Lee Green
2 .\" Program Copyright 1996, 1997 Leonard Zubkoff
3 .\" Extensive changes 2000 by Eric Lee Green <eric@badtux.org>
5 .\" This is free documentation; you can redistribute it and/or
6 .\" modify it under the terms of the GNU General Public License as
7 .\" published by the Free Software Foundation; either version 2 of
8 .\" the License, or (at your option) any later version.
10 .\" The GNU General Public License's references to "object code"
11 .\" and "executables" are to be interpreted as the output of any
12 .\" document formatting or typesetting system, including
13 .\" intermediate and printed output.
15 .\" This manual is distributed in the hope that it will be useful,
16 .\" but WITHOUT ANY WARRANTY; without even the implied warranty of
17 .\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 .\" GNU General Public License for more details.
20 .\" You should have received a copy of the GNU General Public
21 .\" License along with this manual; if not, write to the Free
22 .\" Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139,
27 mtx \- control SCSI media changer devices
29 mtx [-f <scsi-generic-device>] [nobarcode] [invert] [noattach] command [ command ... ]
33 command controls single or multi-drive SCSI media changers such as
34 tape changers, autoloaders, tape libraries, or optical media jukeboxes.
35 It can also be used with media changers that use the 'ATTACHED' API,
36 presuming that they properly report the MChanger bit as required
37 by the SCSI T-10 SMC specification.
39 The first argument, given following
41 , is the SCSI generic device corresponding to your media changer.
42 Consult your operating system's documentation for more information (for
43 example, under Linux these are generally /dev/sg0 through /dev/sg15,
44 under FreeBSD these are /dev/pass0 through /dev/passX,
45 under SunOS it may be a file under /dev/rdsk).
47 The 'invert' option will invert (flip) the media (for optical jukeboxes that
48 allow such) before inserting it into the drive or returning it to the
51 The 'noattach' option forces the regular media changer API even if the
52 media changer incorrectly reported that it uses the 'ATTACHED' API.
54 The 'nobarcode' option forces the loader to not request barcodes even if
55 the loader is capable of reporting them.
57 Following these options there may follow
58 one or more robotics control
59 commands. Note that the 'invert' and 'noattach'
60 options apply to ALL of robotics control
66 Report the mtx version number (e.g. mtx 1.2.8) and exit.
70 Report the product type (Medium Changer, Tape Drive, etc.), Vendor ID,
71 Product ID, Revision, and whether this uses the Attached Changer API
72 (some tape drives use this rather than reporting a Medium Changer on a
73 separate LUN or SCSI address).
76 Make further commands use the regular media changer API rather than the
77 _ATTACHED API, no matter what the "Attached" bit said in the Inquiry info.
78 Needed with some brain-dead changers that report Attached bit but don't respond
82 Makes the robot arm go and check what elements are in the slots. This
83 is needed for a few libraries like the Breece Hill ones that do not
84 automatically check the tape inventory at system startup.
87 Reports how many drives and storage elements are contained in the
88 device. For each drive, reports whether it has media loaded in it, and
89 if so, from which storage slot the media originated. For each storage
90 slot, reports whether it is empty or full, and if the media changer
91 has a bar code, MIC reader, or some other way of uniquely identifying
92 media without loading it into a drive, this reports the volume tag
93 and/or alternate volume tag for each piece of media.
94 For historical reasons drives are numbered from 0 and storage slots are
97 .B load <slotnum> [ <drivenum> ]
98 Load media from slot <slotnum> into drive <drivenum>. Drive 0 is assumed
99 if the drive number is omitted.
101 .B unload [<slotnum>] [ <drivenum> ]
102 Unloads media from drive <drivenum> into slot <slotnum>. If <drivenum> is
103 omitted, defaults to drive 0 (as do all commands).
104 If <slotnum> is omitted, defaults to the slot
105 that the drive was loaded from. Note that there's currently no way to
106 say 'unload drive 1's media to the slot it came from', other than to
107 explicitly use that slot number as the destination.
109 .B [eepos <operation>] transfer <slotnum> <slotnum>
110 Transfers media from one slot to another, assuming that your mechanism is
111 capable of doing so. Usually used to move media to/from an import/export
112 port. 'eepos' is used to extend/retract the import/export
113 tray on certain mid-range to high end tape libraries (if, e.g., the tray was
114 slot 32, you might say say 'eepos 1 transfer 32 32' to extend the tray).
115 Valid values for eepos <operation>
116 are 0 (do nothing to the import/export tray), 1, and 2 (what 1 and 2 do varies
117 depending upon the library, consult your library's SCSI-level
120 .B [eepos <operation>] [invert] [invert2] exchange <slotnum> <slotnum> [<slotnum>]
121 Move medium from the first slot to the second slot, placing the medium
122 currently in the second slot either back into the first slot or into the
126 .B first [<drivenum>]
127 Loads drive <drivenum> from the first slot in the media
128 changer. Unloads the drive if there is already media in it (note: you
129 may need to eject the tape using your OS's tape control commands
130 first). Note that this command may not be what you want on large
131 tape libraries -- e.g. on Exabyte 220, the first slot is usually a
132 cleaning tape. If <drivenum> is omitted, defaults to first drive.
136 Loads drive <drivenum> from the last slot in the media changer. Unloads
137 the drive if there is already a tape in it. (Note: you may need to eject
138 the tape using your OS's tape control commands first).
141 Unloads the drive and loads the next tape in sequence. If the drive was
142 empty, loads the first tape into the drive.
144 .B position <slotnum>
145 Positions the robot at a specific slot. Needed by some changers to
146 move to and open the import/export, or mailbox, slot.
149 The original 'mtx' program was written by Leonard Zubkoff and extensively
150 revised for large multi-drive libraries with bar code readers
151 by Eric Lee Green <eric@badtux.org>. See 'mtx.c' for other contributors.
152 .SH BUGS AND LIMITATIONS
154 You may need to do a 'mt offline' on the tape drive to eject the tape
155 before you can issue the 'mtx unload' command. The Exabyte EZ-17 and 220
156 in particular will happily sit there snapping the robot arm's claws around
157 thin air trying to grab a tape that's not there.
159 For some Linux distributions, you may need to re-compile the kernel to
160 scan SCSI LUN's in order to detect the media changer. Check /proc/scsi/scsi
161 to see what's going on.
163 If you try to unload a tape to its 'source' slot, and said slot is
164 full, it will instead put the tape into the first empty
165 slot. Unfortunately the list of empty slots is not updated between
166 commands on the command line, so if you try to unload another drive to
167 a full 'source' slot during the same invocation of 'mtx', it will try
168 to unload to the same (no longer empty) slot and will urp with a SCSI
172 This program reads the Mode Sense Element Address Assignment Page
173 (SCSI) and requests data on all available elements. For larger
174 libraries (more than a couple dozen elements)
175 this sets a big Allocation_Size in the SCSI command block for the
176 REQUEST_ELEMENT_STATUS command in order to be able to read the entire
177 result of a big tape library. Some operating systems may not be able
178 to handle this. Versions of Linux earlier than 2.2.6, in particular,
179 may fail this request due to inability to find contiguous pages of
180 memory for the SCSI transfer (later versions of Linux 'sg' device do
181 scatter-gather so that this should no longer be a problem).
185 command remains in effect for all further commands on a command
186 line. Thus you might want to follow
187 .B eepos 1 transfer 32 32
191 the next command (which clears the
195 Need a better name for 'eepos' command! ('eepos' is the name of the bit
196 field in the actual low-level SCSI command, and has nothing to do with what
200 This program has only been tested on Linux with a limited number of
201 tape loaders (a dual-drive Exabyte 220 tape library, with bar-code
202 reader and 21 slots, an Exabyte EZ-17 7-slot autoloader, and a Seagate
203 DDS-4 autochanger with 6 slots). It may not work on other operating systems
204 with larger libraries,
205 due to the big SCSI request size.
206 Please see the projecdt page http://sourceforge.net/projects/mtx for information
207 on reporting bugs, requesting features and the mailing list for peer support.
210 .B cat /proc/scsi/scsi
211 will tell you what SCSI devices you have.
212 You can then refer to them as
215 etc. by the order they
219 .B camcontrol devlist
220 will tell you what SCSI devices you
221 have, along with which
223 device controls them.
225 Under Solaris, set up your 'sgen' driver so that it'll look for
226 tape changers (see /kernel/drv/sgen.conf and the sgen man page), type
227 .B touch /reconfigure
228 then reboot. You can find your changer in /devices by typing
229 .B /usr/sbin/devfsadm -C
230 to clean out no-longer-extant entries in your /devices directory, then
231 .B find /devices -name \*changer -print
232 to find the device name. Set the symbolic link
235 to that device name (if it is not doing so already).
237 With BRU, set your mount and unmount commands as described on the BRU
238 web site at http://www.bru.com to move to the next tape when backing up
239 or restoring. With GNU
243 for an example of how to use
247 to make multi-tape backups.
252 is currently being maintained by Robert Nelson <robertnelson@users.sourceforge.net> .
253 The 'mtx' home page is http://mtx.sourceforge.net and the actual code is currently available
254 there and via SVN from http://sourceforge.net/projects/mtx.
256 .BR mt (1), loaderinfo (1), tapeinfo (1), scsitape (1), scsieject (1)