[ltp] ultrabay how recognize it on linux??

[Robert Hajime Lanning]

I have a TP600X.

I have the DVD-ROM, floppy, battery and HD adapter for the UltraSlimBay.

I can warm swap floppy, battery and DVD-ROM.  The hardware will not allow
you to do anything other than a cold swap for the HD adapter.

The trick for accessing the floppy when you did not boot with it, is to
compile the floppy driver as a module.  If it is compiled in staticaly it
only scans at boot.  If compiled as a module it will scan for the floppy
drive every time it loads into the kernel.

So you could load it manualy when you want to use the floppy and unload it
when you are done. Or you can use kerneld or kmod (in kernel version of
kerneld).

---- As written by Thomas Hood:
> 
> Michael Selway wrote:
> > I don't use my hard-disc adapter in the ultrabay solely because of
> > your advice that There Be Dragons if I swap between CD and hard
> > disc without re-booting.  Is the problem "only" that the kernel
> > panics?  I got the impression (not sure where from) that you'd
> > seen data corruption on your internal hard drive.  In the
> > interests of research I'll risk a kernel panic, but I'm not up for
> > data corruption.
> 
> Swapping between devices "cold" (i.e., with power off) is
> no problem.
> 
> It has been reported by "tom" on this list that warm swapping between
> CD-ROM and battery can be done if Linux is booted with the
> "noprobe /dev/hdc" option.  (Shouldn't this be "hdc=noprobe"?)
> 
> It has been reported by Robert Hajime Lanning <lanning@lanning.cc>
> on this list that warm swapping between CD-ROM and floppy drive
> can be done if Linux is booted with the "hdc=cdrom" option.
> 
> I haven't confirmed either of these claims.  I know that when
> I played with this, the only way I could get Linux to recognize
> the floppy drive *ever* was to boot with the floppy drive
> installed in the bay.  That done, I could (in suspend) remove the
> floppy drive and install the CD-ROM drive, (after resume) register
> the secondary ide interface using "hdparm -R", and access the
> CD-ROM drive.  I could switch back and forth between floppy and
> CD-ROM.  However I found that if I didn't unregister the secondary
> ide interface while using the floppy, I would get errors in the
> syslog; whereas if I did unregister it then I got kernel panics.
> Not only did this cause me to have to fsck, but it also seemed
> to corrupt my main filesystem.  Clearly there were bugs in the
> ide driver code at the time (2.2.early).  The ide driver has
> been substantially changed since then so the problem may have
> gone away.  Needs testing.
> 
> Switching between CD-ROM drive and hard drive is a different
> kettle of fish altogether.  Whereas the floppy (and, of course
> the battery) don't use an ide interface at all, the second
> hard drive does.  IIRC, the second hard drive is 
> a second device on the primary ide interface, unlike the
> CD-ROM drive which is attached to the primary ide interface;
> therefore it should appear as hdb rather than as hdc.  So
> far as Linux is concerned, I see no reason why one shouldn't
> be able to warm swap between hard disk and CD-ROM drive by
> doing one of the tricks described above: i.e., either by 
> telling the ide driver about both disks (hdb=yadda hdc=cdrom)
> and/or by dynamically registering and unregistering the
> secondary interface.
> 
> However there may be limitations in the BIOS or in the
> ThinkPad hardware.
> 
> Right now I don't have a second hard disk, and the TP600
> doesn't take a battery in the bay; so all I can test is
> warm swapping between floppy and CD-ROM drives.  I'll
> try it out tomorrow.
> 
> Thomas
> 
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-- 
/* Robert Hajime Lanning                             lanning@lanning.cc
** Trade: Unix Systems Administrator (Senior level) (SAGE IV)
*/
#include <std_disclaimer.h>

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