Backup problem with tape drive on scsi
 

All,

i have a backup script which has been running as a cronjob for sometime with no errors. I have even resotred from the tape in the past so i know all is ok.

Today i have a problem with tape being stuck in the device and wont eject.

My tape device is /dev/st0 and is what i use in the backup script so i know this is correct. when i try to do a mt -f /dev/st0 status I get a no device error message. I have rebooted the server and can see the Tape drive in the DMESG and messages logs from bootup.

I am not sure what could be the problem. I have heard of removing st0 file from /dev and then recreating it using the MAKEDEV command however i am unsure if this where i would need to use this or could it be simply that my drive is broke. I have tried forcing it to eject via a command however i receieve a similar error message. Lights are on the drive etc.

Any help would be greatly appreciated if there is anything i can do to do more troubleshooting.

Below is what i have found in DMESG


SCSI subsystem driver Revision: 1.00
scsi0 : Adaptec AIC7XXX EISA/VLB/PCI SCSI HBA DRIVER, Rev 6.2.8
<Adaptec 29160N Ultra160 SCSI adapter>
aic7892: Ultra160 Wide Channel A, SCSI Id=7, 32/253 SCBs

blk: queue c2428c14, I/O limit 4095Mb (mask 0xffffffff)
Vendor: MAXTOR Model: ATLAS15K2_36SCA Rev: JNZH
Type: Direct-Access ANSI SCSI revision: 03
blk: queue c171b014, I/O limit 4095Mb (mask 0xffffffff)
Vendor: SDR Model: GEM318 Rev: 0
Type: Processor ANSI SCSI revision: 02
blk: queue c171b414, I/O limit 4095Mb (mask 0xffffffff)
scsi0:A:0:0: Tagged Queuing enabled. Depth 253
Attached scsi disk sda at scsi0, channel 0, id 0, lun 0
(scsi0:A:0): 160.000MB/s transfers (80.000MHz DT, offset 127, 16bit)
SCSI device sda: 71833096 512-byte hdwr sectors (36779 MB)

Depends on how it is stuck or what is wrong exactly.

Try pressing on the open button for about 60 seconds or more. Might try that after power cycle.

I am sure there are also rewind commands but I don't know them.

Tape drives are mechanical devices and tapes get stuck, jam or break. As it happens just last week a tape got stuck in one of my DLT drives and now its a big paper weight. It could have also just stopped responding and you can try cycling power to see if it resets itself.

Most likely it is a drive and not a computer problem. Look in the drives manual to see if there is an emergency eject procedure.

Could be just about anything. If `mt -f /dev/st0 status` gives you no such device, and you know that's what your backups had been using, then I would be looking for hardware issues. Power everything down (shutdown the computer, then power off the tape drive), and check that the cables are correctly seated and the terminator is seated or termination settings are proper. When you are confident of that, start up the tape drive and see if the eject button works to spit out the tape. Then start up the computer again and see what happens.

I'm presuming you've made no changes to hardware. But possibly the cat or the janitor or the spouse jostled the cables, or you repositioned the computer or tape drive. These are the easy things. As michaelk said, check the drive's manual. If it's on warranty, call for help. I actually had to disassemble my tape library, extract the drive, and spin a little deal on the circuit board to manually eject a tape. Not much torque on those, and it took hundreds of revolutions to very slowly move the tape dock down and slide it out. Of course, my drive type is different than yours, so no telling what you would run into. Pray for loose cables. ;)

Thanks for the reponse guys, i will check all of the above, however i was just wondering how in dmesg and the messages log it was detected etc after reboot and yet i get the nonsuch device command, i thought if it would be hardware i wouldnt have expected to see it at boot in the logs/dmesg. Thanks

Rob

I guess I missed the fact that you saw no device error message. Are all the SCSI modules loading including st?

I think so, when i look for ls -l st* i see st0 etc, is there something else i should be looking for, are these files where the drivers are stored for the hardware devices on the server?

Thanks again for all the help.

Rob

Compaq External 20/40GB SCSI DDS TD EO2007 (scsi tape drive)
 

Hi,

I am having same problem. My Redhat Enterprise Linux AS 4 unable to detect my scsi tape drive which is attach external scsi.
Following is the output which is generate from
#/sbin/lspci

00:00.0 Host bridge: Intel Corporation 440BX/ZX/DX - 82443BX/ZX/DX Host bridge (AGP disabled) (rev 02)
00:0b.0 VGA compatible controller: Cirrus Logic GD 5446 (rev 45)
00:0d.0 PCI bridge: Digital Equipment Corporation DECchip 21150 (rev 04)
00:0e.0 System peripheral: Compaq Computer Corporation Advanced System Management Controller
00:0f.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5701 Gigabit Ethernet (rev 15)
00:14.0 ISA bridge: Intel Corporation 82371AB/EB/MB PIIX4 ISA (rev 02)
00:14.1 IDE interface: Intel Corporation 82371AB/EB/MB PIIX4 IDE (rev 01)
00:14.2 USB Controller: Intel Corporation 82371AB/EB/MB PIIX4 USB (rev 01)
00:14.3 Bridge: Intel Corporation 82371AB/EB/MB PIIX4 ACPI (rev 02)
01:07.0 Network controller: Compaq Computer Corporation Netelligent Integrated 10/100 TX UTP (rev 10)
01:09.0 SCSI storage controller: LSI Logic / Symbios Logic 53c875 (rev 14)
01:09.1 SCSI storage controller: LSI Logic / Symbios Logic 53c875 (rev 14)
01:0b.0 PCI bridge: IBM PCI to PCI Bridge (IBM27-82351) (rev 07)
02:00.0 Mass storage controller: Compaq Computer Corporation Smart-2/P RAID Controller (rev 03)

Fyi, I include the kernel
#uname -r

2.6.9-82.ELsmp

And, after I run the following command:
mt -f /dev/st0 status
/dev/st0: No such file or directory


Kindly assist, thanks.