# ide-scsi VS ide-cd

## eunuque

Hi all,

I have an ATAPI IDE CDROM and an ATAPI IDE CDRW on my box (hdc and hdd).

As explained in many howtos, to get my CDRW work, I enabled SCSI emulation passing hdd=ide-scsi to the kernel at bootup.

Doing this enables SCSI emulation for BOTH the CDROM and the CDRW. 

So my question is: is it a good thing emulating SCSI for the CDROM?

I realized that passing hdc=ide-cd as kernel boot option makes CDROM use the standard IDE driver; and made few test performances. ide-cd gave me better performances than ide-scsi.

Any thoughts?

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## m0pr0be

up till now ide scsi emulation was needed to get the cdrecord program to recognize atapi devices. otherwise cdrecord wont work. i dont know about other burning applications.

there is some pre-alpha support in the works for cdrecord. with this new interface you wont need to enable ide scsi emulation anymore.

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## TheCoop

atapi recording works perfectly for me, i would consider it beta  :Smile: 

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## blueworm

I am using ATAPI cdrw. I have not noticed any differrence performance wise between this and scsi emulation.

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## eunuque

I use mkisofs/cdrecord/cdrdao to burn cds (I don't care about GUIs).

cdrecord works FINE with scsi emulation.

But may be I was misunderstood.

I was just wondering if it is good to also use scsi emulation for my OTHER CDRom device (just for reading, not burning) and if someone has ever made a performance comparison between ide-cd and ide-scsi drivers?

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## d3c3it

 *TheCoop wrote:*   

> atapi recording works perfectly for me, i would consider it beta 

 

sorry to sound dumb but how exacty did you enable atapi burning? ive just got my kernel compiled with the ide drivers for my mobo but whenever i use k3b or xcdroast it says it needs scsi emulation. I know you have to add the extra line in grub conf to tell the kernel to use scsi for the hdc *which ive not done yet* wondered if i could do it without having to do that ?

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## TheCoop

i use xcdroast, and it just comes up in the device menu as ATAPI devices...

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## Beholders_Eye

I think only K3B 0.10.x suports ATAPI recording. But, I couldn't make it read CD's to make ISO images, through the 'reacd' utility... K3B keeps saying that there's no "reader" available... So, I was not pretending to enable ide-scsi, but, if I want to copy a CD or DVD I'll have to...  :Sad: 

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## olav

 *d3c3it wrote:*   

> sorry to sound dumb but how exacty did you enable atapi burning?

 

First, emerge cdrtools and identify your cd-writer

```
cdrecord dev=ATAPI -scanbus
```

My writer is found as 0,1,0. To test burning, make a directory 'test' and put some files in it. Make an iso image containing the data:

```
mkisofs -f -r -l -o test.iso test
```

Burn the iso:

```
cdrecord -v dev=ATAPI:0,1,0 driveropts=burnfree speed=16 -data test.iso
```

If your drive supports the burnproof technology, use 'driveropts=burnfree', otherwise don't.

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## wolf_99

Hi!

I am tring to get a burner set. I typed in the commands that u said

```

mkisofs -f -r -l -o test.iso test

cdrecord -v dev=ATAPI:0,1,0 driveropts=burnfree speed=16 -data test.iso 
```

and it burnd just butiflly.   :Very Happy: 

but when I do 

```
cdrecord -scanbus
```

 I get

```

Cdrecord-Clone 2.01a19 (i686-pc-linux-gnu) Copyright (C) 1995-2003 Jörg Schilling

Linux sg driver version: 3.1.25

Using libscg version 'schily-0.7'

scsibus0:

        0,0,0     0) '' '' '' Removable not present Disk

        0,1,0     1) *

        0,2,0     2) *

        0,3,0     3) *

        0,4,0     4) *

        0,5,0     5) *

        0,6,0     6) *

        0,7,0     7) *

```

So I figure that I dont have a SCSI simulater. Or am I wrong to assume that?  :Question: 

Now, I don't whant a SCSI imulater, I just whant a nice GUI program, (hopefully GTK/Gnome) that would be simllrer in ease of use to Nero, but can burn without a SCSI simulator.

Can any one help me out here?

P.S. If my qustion is stupid/abscre etc. please explain why, because nothing is obviose for me.   :Confused: 

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## olav

What is the output of 'cdrecord dev=ATAPI -scanbus' ?

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## wolf_99

The eoutput of "cdrecord dev=ATAPI -scanbus" is

```

Cdrecord-Clone 2.01a19 (i686-pc-linux-gnu) Copyright (C) 1995-2003 Jörg Schilling

scsidev: 'ATAPI'

devname: 'ATAPI'

scsibus: -2 target: -2 lun: -2

Warning: Using ATA Packet interface.

Warning: The related libscg interface code is in pre alpha.

Warning: There may be fatal problems.

Using libscg version 'schily-0.7'

scsibus0:

        0,0,0     0) 'LG      ' 'DVD-ROM DRD8160B' '1.03' Removable CD-ROM

        0,1,0     1) 'HL-DT-ST' 'CD-RW GCE-8520B ' '1.00' Removable CD-ROM

        0,2,0     2) *

        0,3,0     3) *

        0,4,0     4) *

        0,5,0     5) *

        0,6,0     6) *

        0,7,0     7) *

```

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## olav

So, everything is allright then. As seen from the output your writer is 0,1,0. Use dev=ATAPI:0,1,0 when burning. You said the command line example I gave you above works fine, so all you have to do when using a GUI program is to tell the program to use the device ATAPI:0,1,0. (Remember that the GUI uses cdrecord to do the burning and that it works in the same way as the command line example).

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## wolf_99

Thanks!

After a bit of tinkering I amnegd to set evry thing to work.

again, thanks!

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## angryelephant

From what I have heard, ide-scsi is just a wrapper around the ide hardware driver to make it look like a scsi device for making cdrecord work. it shouldnt effect performance.

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## marshall_j

The thing I have noticed is the future of ide-scsi is looking murky. This article on Linux.com has some quotes from Linus himself which basically say don't go with ide-scsi if you can help it. 

If you can use 2.6 and ATAPI burning then why bother with the other setup?

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## cult hero

When I run:

```
cdrecord dev=ATAPI -scanbus
```

I get:

```
Cdrecord-Clone 2.01a19 (i686-pc-linux-gnu) Copyright (C) 1995-2003 Jörg Schilling

scsidev: 'ATAPI'

devname: 'ATAPI'

scsibus: -2 target: -2 lun: -2

Warning: Using ATA Packet interface.

Warning: The related libscg interface code is in pre alpha.

Warning: There may be fatal problems.

Using libscg version 'schily-0.7'

scsibus0:

        0,0,0     0) '' '' '' NON CCS Disk

        0,1,0     1) '' '' '' NON CCS Disk

        0,2,0     2) *

        0,3,0     3) *

        0,4,0     4) *

        0,5,0     5) *

        0,6,0     6) *

        0,7,0     7) *
```

Am I missing something in my kernel or is there some other reason it wouldn't recognize with of my DVD-ROM and CD-R drives?

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## cult hero

On the exact same hardware setup when I reboot with test9 (instead of test11) everything works just fine. It recognizes both drives just fine. What could have changed in the kernel?

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## cult hero

And even stranger us this:

```
$ cdrecord dev=/dev/hdc -checkdrive

Cdrecord-Clone 2.01a19 (i686-pc-linux-gnu) Copyright (C) 1995-2003 Jörg Schilling

scsidev: '/dev/hdc'

devname: '/dev/hdc'

scsibus: -2 target: -2 lun: -2

Warning: Open by 'devname' is unintentional and not supported.

Linux sg driver version: 3.5.27

Using libscg version 'schily-0.7'

Device type    : Removable CD-ROM

Version        : 0

Response Format: 1

Vendor_info    : 'TEAC    '

Identifikation : 'CD-W552E        '

Revision       : '1.13'

Device seems to be: Generic mmc CD-RW.

Using generic SCSI-3/mmc   CD-R/CD-RW driver (mmc_cdr).

Driver flags   : MMC-3 SWABAUDIO BURNFREE

Supported modes: TAO PACKET SAO SAO/R96P SAO/R96R RAW/R16 RAW/R96P RAW/R96R
```

It sees my drive fine there but not on the scanbus. Any ideas... anyone?

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## cult hero

All righty, I upgraded to 2.6.0 final tonight and that solved the problem. Someone tipped me off that it was indeed a kernel bug.

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## tatesworld

I just use =/dev/hdx (whatever the cdwriter is connected to)

Ignore 

Warning: Open by 'devname' is unintentional and not supported.

Whats wrong with doing that, It works!

 does it not work for some people?

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## tatesworld

another thing, its damn fast writing with ATAPI than ide-scsi

that was really slow compared to windows, now ATAPI writing is probably even faster now than windows nero etc

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