dead DLT drive? (I/O erors, sense data errors, "write filemark" error)

Gene Heskett gene.heskett at verizon.net
Tue Dec 20 01:17:07 UTC 2005


On Monday 19 December 2005 18:46, Matt Morgan wrote:
>I'm trying, still to get a working Amanda setup. This is on my home
>system in advance of setting it up for a client next week :-). It's
>FC4, and the drive is a Quantum DLT 7000, which I think is a 35/70Gb
>model. It's old.
>
>I think the old DLT drive (haven't used it for a few years, but it
>worked the last time I had it plugged in) may be dead. Here's what I
>notice:
>
>1) The "use cleaning tape" light was on. I plugged in a cleaning
> tape, and the light went out; but then when I plugged i na real
> tape, the drive pretty quickly turned the "use cleaning light" back
> on again. This has happened a few times--the cleaning tape seems to
> work, but then as soon as I put in a real tape, the drive wants
> cleaning again.
>
How old are your tapes, and under what conditions have they been 
stored?

Old tape, particularly if its been stored in a humidity exceeding 50%, 
can get quite abrasive and leave large amounts of oxide gunk on the 
heads rapidly.  I'd also see about getting it (the drive) out of its 
skin and making use of a chamois stick moistened with alcohol (not 
rubbing, its got water in it, use paint thinner or better) to gently 
clean the head, making sure you do not rub it sideways, but in the 
same direction the tape travels.

75F and 80+% relative humidity is death for tape, but only mildly 
uncomfortable for us humans.

Tape, to be of the longest serviceable life, should be stored below 50F 
and 50% relative humidity.  As a broadcast engineer, that item is 
relatively well enforced because it cuts head maintainance by huge 
amounts for the helical scan videotape recorders we used to use.  
They've pretty much been replaced by video servers now, keeping it all 
on big hard drives, many times more dependable in use.

>2) mt fails with I/O errors:
>
>[matt at matt ~]$ sudo mt erase
>Password:
>/dev/tape: Input/output error
>
>3) tar fails similarly:
>
>[matt at matt ~]$ sudo tar -cvf /dev/st0 * .*
>amy/
>bin/
>bin/addressbook.csv
>bin/palm-ldif2csv
>tar: /dev/st0: Cannot write: Input/output error
>tar: Error is not recoverable: exiting now
>
>(in both cases I can tell that it's trying the right device, because
>the drive makes a horrible grinding noise, and the tape spins a
> little bit, before the errors come up).
>
>4) getting errors in /var/log/messages:
>
>Dec 19 18:36:35 matt kernel:     <<vendor>> ASC=0x80 ASCQ=0x1ASC=0x80
> ASCQ=0x1 Dec 19 18:36:35 matt kernel: Info fld=0x1
>Dec 19 18:36:46 matt kernel: st0: Error with sense data: <6>st0:
>Current: sense key: Medium Error
>Dec 19 18:36:46 matt kernel:     <<vendor>> ASC=0x80 ASCQ=0x1ASC=0x80
> ASCQ=0x1 Dec 19 18:36:46 matt kernel: Info fld=0x1
>Dec 19 18:36:46 matt kernel: st0: Error on write filemark.
>
>I've googled those errors, and I can't find anything really pointing
>me to an answer. I've checked termination (this is an Adaptec
>2940U2W), and the card is set to "automatic" on both interfaces,
> which almost always works, in my experience.
>
>For good measure, here are some related lines from dmesg:
>
> target0:0:6: FAST-10 WIDE SCSI 20.0 MB/s ST (100 ns, offset 15)
>st0: Block limits 2 - 16777214 bytes.
>st0: Error with sense data: <6>st0: Current: sense key: Medium Error
>    <<vendor>> ASC=0x80 ASCQ=0x1ASC=0x80 ASCQ=0x1
>----
>Info fld=0x1
>st0: Error on write filemark.
>----
>SCSI subsystem initialized
>PCI: Found IRQ 12 for device 0000:00:0b.0
>PCI: Sharing IRQ 12 with 0000:00:02.1
>scsi0 : Adaptec AIC7XXX EISA/VLB/PCI SCSI HBA DRIVER, Rev 7.0
>        <Adaptec 2940 Ultra2 SCSI adapter>
>        aic7890/91: Ultra2 Wide Channel A, SCSI Id=7, 32/253 SCBs
>
>  Vendor: QUANTUM   Model: DLT7000           Rev: 2150
>  Type:   Sequential-Access                  ANSI SCSI revision: 02
> target0:0:6: Beginning Domain Validation
> target0:0:6: wide asynchronous.
> target0:0:6: Domain Validation skipping write tests
> target0:0:6: FAST-10 WIDE SCSI 20.0 MB/s ST (100 ns, offset 15)
> target0:0:6: Ending Domain Validation
>st: Version 20050830, fixed bufsize 32768, s/g segs 256
>Attached scsi tape st0 at scsi0, channel 0, id 6, lun 0
>st0: try direct i/o: yes (alignment 512 B), max page reachable by HBA
> 1048575
>
>Is there something dumb I've failed to do? Let me know!
>
>Thanks a lot,
>Matt

-- 
Cheers, Gene
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Copyright 2005 by Maurice Eugene Heskett, all rights reserved.




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