[buug] IDE drive recognition

[Jon McClintock]

On Thu, Nov 04, 2004 at 10:53:38AM -0800, f.johan.beisser wrote:
> On Thu, 4 Nov 2004, Aaron T Porter wrote:
> 
> > On Thu, Nov 04, 2004 at 10:31:09AM -0800, Bill Honeycutt wrote:
> > > I'm trying to mount partitions on a secondary drive and I continually
> > > get the following message:
> > >
> > > >  wfh:/# mount -t ext3 /dev/hdc1 /mnt/hdc1/
> > > >  mount: /dev/hdc1 already mounted or /mnt/hdc1/ busy
> >
> >
> > 	How 'bout the output of `dmesg | grep hd` and mount?
> 
> i'm confused.. isn't hdc a hard disk controller?

Nope. In Linux, the controller itself doesn't get a device node, just
the drives. Drive devices have the following scheme:

/ dev / ('hd' or 'sd') ( letter indicating drive ) ( partition number )

'hd' is for IDE devices (Hard drives and most CD-ROMs), 'sd' is for SCSI
disk devices.

Drives are lettered starting with 'a'. In IDE-land, the letters are
allocated two per IDE channel (cable), so the master on channel 0 will
be hda, the slave (if present) will be hdb, and the master on channel 1
will be hdc (typically the CD-ROM drive, if present), and the slave will
be hdd.

To figure what goes where, check the kernel boot log, as Aaron suggests.
It'll tell you what drive has which device, with messages like:

	hda: HITACHI_DK23EA-30, ATA DISK drive
	hdc: Compaq DVD-ROM DV28EB, ATAPI CD/DVD-ROM drive

-Jon