I cannot get the DLT tape drive to work.
Running Suse Linux Enterprise Server v9 sp1 on a Dell 6100/200 with LSI Megaraid Controller/Adaptec 7880 scsi. The DLT-4000 tape drive is on the non-raid controller channel with a cdrom (which works fine), and I've loaded a new Quantum DLTtape IV (40/80 GB), and green light came on. Set the Density Select button to 20.0gb/Compress/Density Override indicators flashing yellow.
I cannot mount the st0 drive or otherwise make use of the tape drive.
Can someone help me? Is there some step I've missed (like "formatting" the tape - remember tape drive newbie here ;-)?

eduapp04:/ # mt -f /dev/st0 status
mt: /dev/st0: Input/output error

Looking in /dev I found a directory /dev/tape/by-path:

eduapp04:/dev/tape/by-path # ls -al
total 0
drwxr-xr-x 2 root root 104 Jan 28 11:44 .
drwxr-xr-x 3 root root 72 Jan 4 05:02 ..
lrwxrwxrwx 1 root root 9 Jan 28 11:44 pci-0000:01:0c.0-scsi-0:0:6:0-generic -> ../../sg1

but /dev/sg1 will not respond to mount either.

eduapp04:/dev # mt -f /dev/sg1 status
mt: /dev/sg1: Operation not permitted
eduapp04:/dev #

From some of the posts here I tried the following commands for some more info: --- and THANKS for any help received!

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eduapp04:~ # dmesg | grep scsi
scsi0 : Adaptec AIC7XXX EISA/VLB/PCI SCSI HBA DRIVER, Rev 6.2.36
(scsi0:A:1): 20.000MB/s transfers (20.000MHz, offset 15)
scsi1 : Adaptec AIC7XXX EISA/VLB/PCI SCSI HBA DRIVER, Rev 6.2.36
scsi2:Found MegaRAID controller at 0xe490, IRQ:20
scsi2 : LSI Logic MegaRAID U.77 254 commands 16 targs 5 chans 7 luns
scsi2: scanning scsi channel 0 for logical drives.
Attached scsi disk sda at scsi2, channel 0, id 0, lun 0
scsi2: scanning scsi channel 4 [P0] for physical devices.
scsi2: scanning scsi channel 5 [P1] for physical devices.
sr0: scsi-1 drive
Attached scsi CD-ROM sr0 at scsi0, channel 0, id 1, lun 0
Attached scsi tape st0 at scsi0, channel 0, id 6, lun 0
Attached scsi generic sg0 at scsi0, channel 0, id 1, lun 0, type 5
Attached scsi generic sg1 at scsi0, channel 0, id 6, lun 0, type 1
Attached scsi generic sg2 at scsi2, channel 0, id 0, lun 0, type 0
Attached scsi generic sg3 at scsi2, channel 4, id 6, lun 0, type 3
Attached scsi generic sg4 at scsi2, channel 4, id 6, lun 1, type 3
Attached scsi generic sg5 at scsi2, channel 4, id 6, lun 2, type 3
Attached scsi generic sg6 at scsi2, channel 4, id 6, lun 3, type 3
Attached scsi generic sg7 at scsi2, channel 4, id 6, lun 4, type 3
Attached scsi generic sg8 at scsi2, channel 4, id 6, lun 5, type 3
Attached scsi generic sg9 at scsi2, channel 4, id 6, lun 6, type 3

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eduapp04:/ # mt -f /dev/st0 status
mt: /dev/st0: Input/output error

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eduapp04:/dev # lsmod
Module Size Used by
vfat 19456 0
fat 49824 1 vfat
usbserial 36080 0
parport_pc 41280 1
lp 15492 0
parport 44232 2 parport_pc,lp
edd 13720 0
joydev 14528 0
sg 41760 0
st 45212 0
sr_mod 21028 0
ide_cd 42628 0
cdrom 43036 2 sr_mod,ide_cd
nvram 13448 0
ipv6 275580 41
af_packet 26376 2
evdev 13952 0
usbcore 116700 2 usbserial
e100 38400 0
mii 9344 1 e100
subfs 12160 2
dm_mod 59904 0
reiserfs 264016 1
megaraid 44104 3
megaraid_mm 15648 0
aic7xxx 198452 1
sd_mod 25088 4
scsi_mod 120132 6 sg,st,sr_mod,megaraid,aic7xxx,sd_mod

************************************************************
eduapp04:/dev # cat /proc/scsi/scsi
Attached devices:
Host: scsi0 Channel: 00 Id: 01 Lun: 00
Vendor: TOSHIBA Model: CD-ROM XM-6401TA Rev: 1009
Type: CD-ROM ANSI SCSI revision: 02
Host: scsi0 Channel: 00 Id: 06 Lun: 00
Vendor: Quantum Model: DLT4000 Rev: CD50
Type: Sequential-Access ANSI SCSI revision: 02
Host: scsi2 Channel: 00 Id: 00 Lun: 00
Vendor: MegaRAID Model: LD0 RAID5 42840R Rev: U.77
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi2 Channel: 04 Id: 06 Lun: 00
Vendor: DELL Model: 6UW BACKPLANE Rev: 7
Type: Processor ANSI SCSI revision: 02
Host: scsi2 Channel: 04 Id: 06 Lun: 01
Vendor: DELL Model: 6UW BACKPLANE Rev: 7
Type: Processor ANSI SCSI revision: 02
Host: scsi2 Channel: 04 Id: 06 Lun: 02
Vendor: DELL Model: 6UW BACKPLANE Rev: 7
Type: Processor ANSI SCSI revision: 02
Host: scsi2 Channel: 04 Id: 06 Lun: 03
Vendor: DELL Model: 6UW BACKPLANE Rev: 7
Type: Processor ANSI SCSI revision: 02
Host: scsi2 Channel: 04 Id: 06 Lun: 04
Vendor: DELL Model: 6UW BACKPLANE Rev: 7
Type: Processor ANSI SCSI revision: 02
Host: scsi2 Channel: 04 Id: 06 Lun: 05
Vendor: DELL Model: 6UW BACKPLANE Rev: 7
Type: Processor ANSI SCSI revision: 02
Host: scsi2 Channel: 04 Id: 06 Lun: 06
Vendor: DELL Model: 6UW BACKPLANE Rev: 7
Type: Processor ANSI SCSI revision: 02

POSSIBLY SOLVED! Our school received a donation of 2 Dell 6100s and I caniballized one of them for it's DLT4000 drive; tried this other unit in the problem machine and Presto! it seems to work fine. Original DLT drive has a hardware problem I guess.
Thanks to the forum for many other clues on how to approach this,and one in particular for a backup script I'm putting to use with some mods...

Regards,

NeilB