Hello ,
1. you need supported scsi adapter - LTO is produced in two versions - LVD
and HVD -
    FC 6204 HVD Ult (PCI)
    FC 6207 HVD Ult (PCI)
    FC 6205 LVD Ult2 (PCI)
    Integrated LVD
    are supported on AIX
2. you need upgrade your TSM to minimum 3.7.4 version
3. install device driver for LTO and 3583 (
ftp://service.boulder.ibm.com/storage/devdrvr/AIX )
4. read 3.7.4 readme about 3583 configuration
    this is from 4.1.1 version

   **********************************************************************
 * $$1 Support for LTO Tape Drives                                    *
 **********************************************************************

 Please note the words "LTO Ultrium" are trademarked.

 Support for IBM 3580, 3581, 3583 and 3584 LTO Ultrium products. The IBM
3580
 is a stand-alone drive.  The IBM 3581, 3583 and 3584 are automated
libraries.

 TSM supports the IBM 3580, 3581, 3583 and 3584 LTO Ultrium products on the
AIX,
 NT 4.0 and NT 5.0 platforms.

 Users must use the SSD RMSS device drivers on these platforms to recognize
and
 configure the IBM 3580, 3581, 3583 and 3584.  To obtain the correct level
of the
 device driver, review the README files in the
ftp.software.ibm.com/storage/devdrvr.

 To define the device class, users should use the following:
 DEFINE DEVCLASS device_class_name DEVTYPE=LTO
        FORMAT=[DRIVE or ULTRIUM or ULTRIUMC]

LIBRARY=library_name

 NOTE: For RSM, the DEVTYPE is LTO instead of GENERICTAPE. All other devices
will
       continue to be defined with DEVTYPE=GENERICTAPE.

 On the AIX and NT 4.0 platforms, users should define the IBM 3581, 3583 and
3584
 products as follows:

 DEFINE LIBRARY library_name LIBTYPE=SCSI DEVICE=<device_special_file>

 On the AIX and NT 4.0 platforms, users should define the drives within
those
 libraries as follows:

 DEFINE DRIVE library_name drive_name DEVICE=<device_special_file>
        ELEMENT=<element_number>

 On Windows 2000 platforms, users should define the IBM 3581, 3583 and 3584
products
 as follows:

 DEFINE LIBRARY library_name LIBTYPE=RSM MEDIATYPE="LTO Ultrium"

 Note that the quotes around "LTO Ultrium" are required.
 Users should use standard RSM configuration techniques.

 For example, on AIX, assuming AIX recognized and configured the medium
changer as
 /dev/smc0 and the drive as /dev/rmt0:
 DEFINE LIBRARY 3584LIB LIBTYPE=SCSI DEVICE=/dev/smc0
 DEFINE DRIVE 3584lib rmt0 DEVICE=/dev/rmt0 ELEMENT=104

 For example, on the NT 4.0, assuming NT recognized and configured the
medium changer
 as \\.\lb3.1.0.2 and the drive as \\.\Tape0:

 DEFINE LIBRARY 3584LIB LIBTYPE=SCSI DEVICE=\\.\lb3.1.0.2
 DEFINE DRIVE 3584lib tape0 DEVICE=\\.\Tape0 ELEMENT=104

 For example, on Windows 2000, assuming Windows 2000 recognized and
configured the
 medium  changer as \\.\Changer0 and the drive as \\.\Tape0:

 DEFINE LIBRARY 3584LIB LIBTYPE=RSM MEDIATYPE="LTO Ultrium"
 Note that the quotes around "LTO Ultrium" are required.

 At this time the DSMLABEL utility and the Tape Labeling Wizard do not
support this
 new family of products.  Users should use the LABEL LIBVOLUME command.


Good Luck
                     Petr