Dont understand hdc=ide-scsi behaviour.

Dont understand hdc=ide-scsi behaviour.

[Reg Clemens]

I dont understand the behaviour of kernel 2.4.18 (and probably all others) when
I put the line
		hdc=ide-scsi
on the load line.

I would EXPECT to get the ide-scsi driver for hdc (my cdwriter) but instead 
get it for BOTH hdc and hdd, the cdwriter and the zip drive.

After starting this way (with hdc=ide-scsi), I find that 
	/dev/cdrom2 -> /dev/scd0
and that to access the zip drive I have to use /dev/sda1 (or /dev/sda4)

I would EXPECT to get to them via /dev/hdd1 or /dev/hdd4.

Did I miss something or is this a bug????

				Reg.Clemens
				reg@dwf.com

Re: Dont understand hdc=ide-scsi behaviour.

[Allan Duncan]

Reg Clemens wrote:
> 
> I dont understand the behaviour of kernel 2.4.18 (and probably all others) when
> I put the line
>                 hdc=ide-scsi
> on the load line.
> 
> I would EXPECT to get the ide-scsi driver for hdc (my cdwriter) but instead
> get it for BOTH hdc and hdd, the cdwriter and the zip drive.
> 
> After starting this way (with hdc=ide-scsi), I find that
>         /dev/cdrom2 -> /dev/scd0
> and that to access the zip drive I have to use /dev/sda1 (or /dev/sda4)
> 
> I would EXPECT to get to them via /dev/hdd1 or /dev/hdd4.
> 
> Did I miss something or is this a bug????

I presume you are putting the "hdc=ide-scsi" as a kernel param.
I do similarly, EXCEPT the CDwriter is on its own IDE bus.
I suspect that the hdc=ide-scsi thing will apply to both master and slave
on an IDE channel - whether that is intended/mandated I can't say.
If you move the zip to hdb all should be well, or buy an IDE PiC and get
more channels if you have run out.

Re: Dont understand hdc=ide-scsi behaviour.

[Andre Hedrick]

Because only the lastest code base under -ac and maybe 2.5 is beginning to
to be device selectable.

hdc=scsi
insmod ide-cd
insmod ide-scsi

Be done

Cheers,

Andre Hedrick
LAD Storage Consulting Group

On Thu, 19 Sep 2002, Reg Clemens wrote:

> 
> I dont understand the behaviour of kernel 2.4.18 (and probably all others) when
> I put the line
> 		hdc=ide-scsi
> on the load line.
> 
> I would EXPECT to get the ide-scsi driver for hdc (my cdwriter) but instead 
> get it for BOTH hdc and hdd, the cdwriter and the zip drive.
> 
> After starting this way (with hdc=ide-scsi), I find that 
> 	/dev/cdrom2 -> /dev/scd0
> and that to access the zip drive I have to use /dev/sda1 (or /dev/sda4)
> 
> I would EXPECT to get to them via /dev/hdd1 or /dev/hdd4.
> 
> Did I miss something or is this a bug????
> 
> 				Reg.Clemens
> 				reg@dwf.com
> -
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Re: Dont understand hdc=ide-scsi behaviour.

[Brad Hards]

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On Fri, 20 Sep 2002 07:08, Reg Clemens wrote:
> I dont understand the behaviour of kernel 2.4.18 (and probably all others)
> when I put the line
> 		hdc=ide-scsi
> on the load line.
>
> I would EXPECT to get the ide-scsi driver for hdc (my cdwriter) but instead
> get it for BOTH hdc and hdd, the cdwriter and the zip drive.
>
> After starting this way (with hdc=ide-scsi), I find that
> 	/dev/cdrom2 -> /dev/scd0
> and that to access the zip drive I have to use /dev/sda1 (or /dev/sda4)
There are two slightly different things happening, I think.

1. When you say hdc=ide-scsi, you are telling the IDE system that you don't 
want to use the normal IDE interfaces to userland (such as ide-cdrom), but 
instead want all access to this device to be accessed through the SCSI 
midlayer (and associated SCSI interfaces, like the sg and scd drivers). So 
ide-scsi becomes the driver, instead of ide-cdrom. You should be able to see 
this in /proc/ide/hdc/driver

2. ide-scsi is greedy, and will grab any IDE device without a driver. ATAPI 
floppy devices (hopefully) like your zip drive need the IDE floppy device 
driver, which is probably not loaded. What does CONFIG_BLK_DEV_IDEFLOPPY 
equal in your kernel config?

> I would EXPECT to get to them via /dev/hdd1 or /dev/hdd4.
And you will, with the right driver loaded :-)

> Did I miss something or is this a bug????
If you load ide-floppy before ide-scsi, and it still doesn't work, then there 
is a bug.

Brad
- -- 
http://conf.linux.org.au. 22-25Jan2003. Perth, Australia. Birds in Black.
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Re: Dont understand hdc=ide-scsi behaviour.

[Miles Lane]

On Thu, 2002-09-19 at 23:46, Brad Hards wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 
> On Fri, 20 Sep 2002 07:08, Reg Clemens wrote:
> > I dont understand the behaviour of kernel 2.4.18 (and probably all others)
> > when I put the line
> > 		hdc=ide-scsi
> > on the load line.
> >
> > I would EXPECT to get the ide-scsi driver for hdc (my cdwriter) but instead
> > get it for BOTH hdc and hdd, the cdwriter and the zip drive.
> >
> > After starting this way (with hdc=ide-scsi), I find that
> > 	/dev/cdrom2 -> /dev/scd0
> > and that to access the zip drive I have to use /dev/sda1 (or /dev/sda4)
> There are two slightly different things happening, I think.
> 
> 1. When you say hdc=ide-scsi, you are telling the IDE system that you don't 
> want to use the normal IDE interfaces to userland (such as ide-cdrom), but 
> instead want all access to this device to be accessed through the SCSI 
> midlayer (and associated SCSI interfaces, like the sg and scd drivers). So 
> ide-scsi becomes the driver, instead of ide-cdrom. You should be able to see 
> this in /proc/ide/hdc/driver
> 
> 2. ide-scsi is greedy, and will grab any IDE device without a driver. ATAPI 
> floppy devices (hopefully) like your zip drive need the IDE floppy device 
> driver, which is probably not loaded. What does CONFIG_BLK_DEV_IDEFLOPPY 
> equal in your kernel config?
> 
> > I would EXPECT to get to them via /dev/hdd1 or /dev/hdd4.
> And you will, with the right driver loaded :-)
> 
> > Did I miss something or is this a bug????
> If you load ide-floppy before ide-scsi, and it still doesn't work, then there 
> is a bug.

Well, aren't things going to get even more confusing when we 
try to support devices like the Lacie DVD/CD Rewritable 
combo drive?  Are we going to do a better job of simply making 
all usable interfaces available, so we no longer need to switch
between drivers or twiddle driver load order?

	Miles

Re: Dont understand hdc=ide-scsi behaviour.

[Brad Hards]

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WARNING: this email is even more clueless than my normal posting standard.

On Sat, 21 Sep 2002 00:46, Miles Lane wrote:
> Well, aren't things going to get even more confusing when we
> try to support devices like the Lacie DVD/CD Rewritable
> combo drive?  Are we going to do a better job of simply making
> all usable interfaces available, so we no longer need to switch
> between drivers or twiddle driver load order?


Don't know the product, but I take it that this is a single IDE drive that can 
read and write CDs, and read (and perhaps write) DVDs? If you want to write, 
use ide-scsi+sg+scd, else just use ide-cdrom.

Until we have another userspace and kernel combination for writing, you are 
stuck with cdrecord and sg. It'd be an vaguelly interesting exercise to have 
a CD burning app that worked natively with ide-cdrom, but I have about a 
million more important things to do before I'd start on that :)

If anyone is interested in coding this, what I'd really like to see is a CD 
burning library that works with sg and ide-cdrom. You'd probably need to 
modify ide-cdrom - I have no real idea about ATAPI or any other block device. 

Then we could move away from GUIs that are really all just running the same 
command line application, and get some more interesting handling going. 

Brad

- -- 
http://conf.linux.org.au. 22-25Jan2003. Perth, Australia. Birds in Black.
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Re: Dont understand hdc=ide-scsi behaviour.

[Paul Bristow]

Use the line
    hdc=ide-scsi hdd=ide-floppy

and all should be well, even if using ide-floppy as a module

Miles Lane wrote:

>On Thu, 2002-09-19 at 23:46, Brad Hards wrote:
>  
>
>>-----BEGIN PGP SIGNED MESSAGE-----
>>Hash: SHA1
>>
>>On Fri, 20 Sep 2002 07:08, Reg Clemens wrote:
>>    
>>
>>>I dont understand the behaviour of kernel 2.4.18 (and probably all others)
>>>when I put the line
>>>		hdc=ide-scsi
>>>on the load line.
>>>
>>>I would EXPECT to get the ide-scsi driver for hdc (my cdwriter) but instead
>>>get it for BOTH hdc and hdd, the cdwriter and the zip drive.
>>>
>>>After starting this way (with hdc=ide-scsi), I find that
>>>	/dev/cdrom2 -> /dev/scd0
>>>and that to access the zip drive I have to use /dev/sda1 (or /dev/sda4)
>>>      
>>>
>>There are two slightly different things happening, I think.
>>
>>1. When you say hdc=ide-scsi, you are telling the IDE system that you don't 
>>want to use the normal IDE interfaces to userland (such as ide-cdrom), but 
>>instead want all access to this device to be accessed through the SCSI 
>>midlayer (and associated SCSI interfaces, like the sg and scd drivers). So 
>>ide-scsi becomes the driver, instead of ide-cdrom. You should be able to see 
>>this in /proc/ide/hdc/driver
>>
>>2. ide-scsi is greedy, and will grab any IDE device without a driver. ATAPI 
>>floppy devices (hopefully) like your zip drive need the IDE floppy device 
>>driver, which is probably not loaded. What does CONFIG_BLK_DEV_IDEFLOPPY 
>>equal in your kernel config?
>>    
>>
-- 

Paul

Email:	paul@paulbristow.net
Web:	http://paulbristow.net
ICQ:	11965223