[sclug] Problem with CD drives after rebuild

[Tom Carbert-Allen]

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.
>>
>>