[sclug] Problem with CD drives after rebuild

[Neil Haughton]

Tom,

Thanks for thoughts. I've made some progress:

1. One of the drives is a CD writer and I was trying to mount a DVD, I've
realised (Doh!). That offers an explanation why the CD drive wouldn't mount
but not why the DVD drive won't. I feel a bit of a fool not seeing the wood
for the trees and all that, but it isn't the root problem.
2. I have disconnected each of the drives in turn. At boot the BIOS
correctly recognises them as master or slave (respectively), and whichever
one is connected will automount a CD (and /dev/hdc, which is the DVD drive,
will also automount a DVD). It seems therefore that the problem arises when
they are both connected. Perhaps my only recourse now is to replace the
cable when I can scrounge one to try out. If that solves the problem I know
what I have to do. If not.....

Regards,

Neil.


2009/4/12 Tom Carbert-Allen <tom at randominter.net>

> thoughts:
> the drives are set master/slave but are connected at the wrong end of the
> cable (some cables have one pin disconnected to the final plug for cable
> select setups) (check jumpers and drive ordering)
> one of the drives is set to master no slave present (check jumpers on back)
> the cables aren't plugged in properly, or the ribbon cable has come loose
> from the plug (try a different cable)
> interference on the cable, try upgrading to a udma133 cable, and use real
> ribbon cables not ribbon cables cut and rammed into a round plastic tube
> (unlikely)
> one of the drives has lost it's mind (try them one at a time)
> look in logs for bus errors
>
> one thing that does disappoint me though is that Ubuntu can still grind to
> a halt because of a broken IO wait, ideally the system wouldn't grind to a
> halt in this situation, although I imagine if the IDE bus is jammed and the
> chipset doesn't support independent access of each socket, then there is
> little the kernel can do if it can't get files off the disk to run your
> shutdown command. You would think that the device scheduler would still
> offer prompt response from keyboard/mouse though? Or maybe it's device
> interupt problem at the chipset level, the CD drive blocking the chipset
> preventing your mouse movements getting thru? that is surely bad chipset
> design though..... but that is always the difference between consumer grade
> and high end servers, they bung everything on one chip and you are buggared
> if any one part has a problem.
>
> TCA
>
>
>
> Neil Haughton wrote:
>
>> Hi Alex,
>>
>> Answers inserted below. At the risk of labouring the point, all I have
>> done
>> as far as I am aware is move kit from one case to a smaller case. On the
>> face of it all that has changed is the sheet-metal work:
>>
>> 2009/4/11 Alex Butcher <lug at assursys.co.uk>
>>
>>
>>
>>> On Sat, 11 Apr 2009, Neil Haughton wrote:
>>>
>>>  $ mount /dev/hdd
>>>
>>>
>>>> mount: No medium found
>>>>
>>>> Any ideas?
>>>>
>>>>
>>>>
>>> What does running
>>>
>>>       hdparm -i /dev/hdc && hdparm -i /dev/hdd
>>>
>>> as root say?
>>>
>>>
>>
>>
>> $ sudo hdparm -i /dev/hdc
>> [sudo] password for neil:
>>
>> /dev/hdc:
>>
>>  Model=SAMSUNG DVD-ROM SD-616F, FwRev=F100, SerialNo=
>>  Config={ Fixed Removeable DTR<=5Mbs DTR>10Mbs nonMagnetic }
>>  RawCHS=0/0/0, TrkSize=0, SectSize=0, ECCbytes=0
>>  BuffType=unknown, BuffSize=0kB, MaxMultSect=0
>>  (maybe): CurCHS=0/0/0, CurSects=0, LBA=yes, LBAsects=0
>>  IORDY=yes, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
>>  PIO modes:  pio0 pio1 pio2 pio3 pio4
>>  DMA modes:  sdma0 sdma1 sdma2 mdma0 mdma1 mdma2
>>  UDMA modes: udma0 udma1 *udma2
>>  AdvancedPM=no
>>
>>  * signifies the current active mode
>>
>> neil at study:~$ sudo hdparm -i /dev/hdd
>>
>> /dev/hdd:
>>
>>  Model=HL-DT-ST GCE-8483B, FwRev=B105, SerialNo=
>>  Config={ Fixed Removeable DTR<=5Mbs DTR>10Mbs nonMagnetic }
>>  RawCHS=0/0/0, TrkSize=0, SectSize=0, ECCbytes=0
>>  BuffType=unknown, BuffSize=0kB, MaxMultSect=0
>>  (maybe): CurCHS=0/0/0, CurSects=0, LBA=yes, LBAsects=0
>>  IORDY=yes, tPIO={min:227,w/IORDY:120}, tDMA={min:120,rec:120}
>>  PIO modes:  pio0 pio1 pio2 pio3 pio4
>>  DMA modes:  mdma0 mdma1 mdma2
>>  UDMA modes: udma0 udma1 *udma2
>>  AdvancedPM=no
>>
>>  * signifies the current active mode
>>
>>
>>
>>
>>
>>> What happens if you run
>>>
>>>       eject /dev/hdc
>>>
>>> and
>>>       eject /dev/hdd
>>> ?
>>>
>>>
>>
>>
>> Both open the drive drawers as you would expect.
>>
>>
>>
>>> What's the output of
>>>
>>>       ls -Al /dev | grep 'hd[cd]'
>>>
>>>
>>
>> ?
>>
>>
>> $ ls -Al /dev | grep 'hdd'
>> lrwxrwxrwx 1 root   root             3 2009-04-12 10:32 cdrom1 -> hdd
>> lrwxrwxrwx 1 root   root             3 2009-04-12 10:32 cdrw1 -> hdd
>> brw-rw---- 1 root   cdrom      22,  64 2009-04-12 10:32 hdd
>>
>>  $ ls -Al /dev | grep 'hdc'
>> lrwxrwxrwx 1 root   root             3 2009-04-12 10:32 cdrom -> hdc
>> lrwxrwxrwx 1 root   root             3 2009-04-12 10:32 dvd -> hdc
>> brw-rw---- 1 root   cdrom      22,   0 2009-04-12 10:32 hdc
>>
>>
>> In conclusion, it looks to me that the drives are correctly wired up, the
>> OS
>> can see and  operate them, and YET, I cannot mount an inserted CD.  What
>> happens is this: with no CD in the drive,
>>
>> $ mount /dev/hdd
>>
>> has the immediate response
>>
>> mount: No medium found
>>
>> Doing the same command with a CD in the drawer results in the drawer
>> closing, a long pause with the CD light flashing, then the same output
>> message - no medium found.
>>
>> $ mount /dev/hdc
>>
>> has the immediate response
>>
>> mount: No medium found
>>
>> ON the other hand, doing the same command with a CD in the drawer results
>> in
>> the drawer closing, then the CD spins up to full speed and that's that, it
>> stays that way. The machine is virtually unusable because it seems to be
>> IO
>> bound. I can get a response to keyboard/mouse at about 10 second
>> intervals.
>> A top command shows nothing particularly using processor cycles so I guess
>> it must be an IO issue. Even issuing a shutdown command as root will not
>> work. I eventually have to switch off or do a hard reset.
>>
>> Have I just got two non-working drives? I suppose it is possible that in
>> transferring both drives to the new case they could both have become
>> physically damaged, careful though I was, but it seems an unlikely
>> probability don't you think? One perhaps, both unlikely, so I am hoping
>> there is something else at work here.
>>
>> Regards,
>>
>> Neil.
>>
>>
>>
>>
>>
>>
>>> Cheers,
>>> Alex.
>>>
>>>
>>>
>>