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mtx -- a native linux media changer tool

ipstor

01 Jul 2021 — 6 min read

media changer tool

mtx is a native linux media changer tool, it controls SCSI media changer devices.The mtx command controls single or multi-drive SCSI media changers such as tape changers, autoloaders, tape libraries, or optical media jukeboxes. It can also be used with media changers that use the ’ATTACHED’ API, presuming that they properly report the MChanger bit as required by the SCSI T-10 SMC specification.
In this article, same as others, I’ll show you examples of mtx usage, in my case, it’s version 1.3.12

Package info

$rpm -ql mtx-1.3.12-501.sl6.x86_64/usr/sbin/loaderinfo/usr/sbin/mtx/usr/sbin/mtx-driveinfo/usr/sbin/mtx-inventory/usr/sbin/scsieject/usr/sbin/scsitape/usr/sbin/tapeinfo…mtx-driveinfo and mtx-inventory are hacked by me for particular purpose, will tell you more in other articles.

SYNOPSIS

mtx [-f <scsi-generic-device>] [nobarcode] [invert] [noattach] command [ command … ]The list of the commands of mtx:
Inquiry, Inventory, status, load, unload, transfer, Invert, First, Last, Next, Position, Eject
Here are examples for these commands

Inquiry

Inquiry Report the product type (Medium Changer, Tape Drive, etc.), Vendor ID, Product ID, Revision, and whether this uses the Attached Changer API (some tape drives use this rather than reporting a Medium Changer on a separate LUN or SCSI address).
# mtx -f /dev/changer3 inquiryProduct Type: Medium ChangerVendor ID: ‘IBM ‘Product ID: ‘03584L32 ‘Revision: ‘B540’Attached Changer API: No

Inventory — not applicable to all libraries

Inventory Makes the robot arm go and check what elements are in the slots. This is needed for a few libraries like the Breece Hill ones that do not automatically check the tape inventory at system startup.

Status

Reports how many drives and storage elements are contained in the device. For each drive, reports whether it has media loaded in it, and if so, from which storage slot the media originated.
For each storage slot, reports whether it is empty or full, and if the media changer has a bar code, MIC reader, or some other way of uniquely identifying media without loading it into a drive, this reports the volume tag and/or alternate volume tag for each piece of media.
For historical reasons drives are numbered from 0 and storage slots are numbered from 1.
# mtx -f /dev/changer3 status Storage Changer /dev/changer3:1 Drives, 46 Slots ( 16 Import/Export )Data Transfer Element 0:Full (Storage Element 3 Loaded):VolumeTag = A04592 Storage Element 1:Full :VolumeTag=A04590 Storage Element 2:Full :VolumeTag=A04591 Storage Element 3:Empty:VolumeTag= Storage Element 4:Full :VolumeTag=A04593 Storage Element 5:Full :VolumeTag=A04594 Storage Element 6:Full :VolumeTag=A04595 Storage Element 7:Full :VolumeTag=A04596 Storage Element 8:Full :VolumeTag=A04597 Storage Element 9:Full :VolumeTag=A04598 Storage Element 10:Full :VolumeTag=A04599 Storage Element 11:Empty:VolumeTag= Storage Element 12:Empty:VolumeTag= Storage Element 13:Empty:VolumeTag= Storage Element 14:Empty:VolumeTag= Storage Element 15:Empty:VolumeTag= Storage Element 16:Empty:VolumeTag=…

Load

Load media from slot <slotnum> into drive <drivenum>. Drive 0 is assumed if the drive number is omitted.
load <slotnum> [ <drivenum> ]# mtx -f /dev/changer3 load 3 0Loading media from Storage Element 3 into drive 0…done

Unload

unload [<slotnum>] [ <drivenum> ]Unloads media from drive <drivenum> into slot <slotnum>. If <drivenum> is omitted, defaults to drive 0 (as do all commands). If <slotnum> is omitted, defaults to the slot that the drive was loaded from.Note that there’s currently no way to say ’unload drive 1’s media to the slot it came from’, other than to explicitly use that slot number as the destination.
# mtx -f /dev/changer3 unload 3 0Unloading drive 0 into Storage Element 3…done

Transfer

[eepos <operation>] transfer <slotnum> <slotnum>Transfers media from one slot to another, assuming that your mechanism is capable of doing so. Usually used to move media to/from an import/export port. ’eepos’ is used to extend/retract the import/export tray on certain mid-range to high end tape libraries (if, e.g., the tray was slot 32, you might say say ’eepos 1 transfer 32 32’ to extend the tray). Valid values for eepos <operation> are 0 (do nothing to the import/export tray), 1, and 2 (what 1 and 2 do varies depending upon the library,consult your library’s SCSI-level documentation).# mtx -f /dev/changer3 transfer 10 11# mtx -f /dev/changer3 status Storage Changer /dev/changer3:1 Drives, 46 Slots ( 16 Import/Export )Data Transfer Element 0:Full (Storage Element 3 Loaded):VolumeTag = A04592 Storage Element 1:Full :VolumeTag=A04590 Storage Element 2:Full :VolumeTag=A04591 Storage Element 3:Empty:VolumeTag= Storage Element 4:Full :VolumeTag=A04593 Storage Element 5:Full :VolumeTag=A04594 Storage Element 6:Full :VolumeTag=A04595 Storage Element 7:Full :VolumeTag=A04596 Storage Element 8:Full :VolumeTag=A04597 Storage Element 9:Full :VolumeTag=A04598 Storage Element 10:Empty:VolumeTag= Storage Element 11:Full :VolumeTag=A04599…

Invert

— I don’t even see use case for this option [eepos <operation>] [invert] [invert2] exchange <slotnum> <slotnum> [<slotnum>]Move medium from the first slot to the second slot, placing the medium currently in the second slot either back into the first slot or into the optional third slot.

First

first [<drivenum>]Loads drive <drivenum> from the first slot in the media changer. Unloads the drive if there is already media in it (note: you may need to eject the tape using your OS’s tape control commands first). Note that this command may not be what you want on large tape libraries — e.g. on Exabyte 220, the first slot is usually a cleaning tape.
If <drivenum> is omitted, defaults to first drive.
# mtx -f /dev/changer3 firstUnloading drive 0 into Storage Element 3…doneLoading media from Storage Element 1 into drive 0…done

Last

last [<drivenum>]Loads drive <drivenum> from the last slot in the media changer. Unloads the drive if there is already a tape in it.(Note: you may need to eject the tape using your OS’s tape control commands first).
# mtx -f /dev/changer3 lastUnloading drive 0 into Storage Element 1…doneLoading media from Storage Element 30 into drive 0…Source Element Address 1056 is EmptyNote: there is no tape in the last slot in this case

next [<drivenum>]Unloads the drive and loads the next tape in sequence. If the drive was empty, loads the first tape into the drive.# mtx -f /dev/changer3 nextLoading media from Storage Element 1 into drive 0…done

Position

position <slotnum>Positions the robot at a specific slot. Needed by some changers to move to and open the import/export, or mailbox, slot.# mtx -f /dev/changer3 position 10

Eject

eject, eject tape from tape drive, no robot movement.

Other tools in the same package

In addition to mtx tool, there are other tools in mtx package

loaderinfo

Usage: loaderinfo -f <generic-device>
# loaderinfo -f /dev/changer3Product Type: Medium ChangerVendor ID: ‘IBM ‘Product ID: ‘03584L32 ‘Revision: ‘B540’Attached Changer: NoBar Code Reader: NoEAAP: YesNumber of Medium Transport Elements: 2Number of Storage Elements: 30Number of Import/Export Elements: 16Number of Data Transfer Elements: 1Transport Geometry Descriptor Page: YesInvertable: NoDevice Configuration Page: YesStorage: Data Transfer, Import/Export, StorageSCSI Media Changer (rev 2): NoTransfer Medium Transport: ->Data Transfer, ->Import/Export, ->StorageTransfer Storage: ->Data Transfer, ->Import/Export, ->StorageTransfer Import/Export: ->Data Transfer, ->Import/Export, ->StorageTransfer Data Transfer: ->Data Transfer, ->Import/Export, ->StorageExchange Medium Transport: NoneExchange Storage: <>Data Transfer, <>Import/Export, <>StorageExchange Import/Export: <>Data Transfer, <>Import/Export, <>StorageExchange Data Transfer: <>Data Transfer, <>Import/Export, <>Storage

tapeinfo

# tapeinfo /dev/fcnst18Usage: tapeinfo -f <generic-device>[root@t1-ppshead ~]# tapeinfo -f /dev/fcnst18Product Type: Tape DriveVendor ID: ‘IBM ‘Product ID: ‘ULT3580-TD5 ‘Revision: ‘BBNE’Attached Changer API: NoSerialNumber: ‘00078A2295’MinBlock: 1MaxBlock: 8388608SCSI ID: 1SCSI LUN: 0Ready: yesBufferedMode: yesMedium Type: 0x58Density Code: 0x58BlockSize: 0DataCompEnabled: noDataCompCapable: yesDataDeCompEnabled: yesCompType: 0x1DeCompType: 0x1BOP: yesBlock Position: 0Partition 0 Remaining Kbytes: -1Partition 0 Size in Kbytes: -1ActivePartition: 0EarlyWarningSize: 0NumPartitions: 0MaxPartitions: 1

scsieject — unlike mtx, this is to control SCSI tape devices, as well as CD/DVD

The scsieject command controls SCSI devices in a platform-independent manner. As long as ‘mtx’ works on the platform, so does ‘scsieject’.

Usage:

scsieject [-f <scsi-generic-device>] commands

COMMANDS

load Load the medium into the drive. When this command is issued to a CD/DVD drive and the tray is extended the tray will be retracted if the drive is capable of it.unload Unload the medium from the drive (also known as eject). When this command is issued to a CD/DVD drive or a tape drive the media will be ejected if the device supports it.start Start the device. Some devices require a start command after a media changer has loaded new media into the device.stop Stop the device. Some devices require a stop command prior to unloading the medium from the device when using a media changer.lock Lock the device. Locks the device so that the medium cannot be removed manually.unlock Unlock the device. Unlocks the device so that the medium can be removed manually.

scsitape

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