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palanisaravanan

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Basic question abt SCSI

I have an IDE hard disk(Samsung).I installed Knoppix on my hard disk and started using it.
 
   when I checked the lilo.conf it tried to pass a command line argument
hda=scsi,hdb=scsi
where hda is my hard disk and hdb is my cdrom.(I didn't made any changes to lilo.conf,The lilo.conf is automatically created during knoopix installation).
In kernel SCSI support is enabled and IDE-SCSI emulation is also enabled.
 
   By passing those above mentioned parametes, I think it is trying to use my IDE disk as SCSI disk . AM I CORRECT?.

I have some  qns.
    1.Is it  possible to use a IDE disk as a SCSI disk just by passing these parameter to kernel  and enabling support for SCSI in kernel?.
   2.I want to know whether my HD is detected as IDE or SCSI.
   For this i checked my dmesg.The message is
**********************************************************
hda: ST340015A, ATA DISK drive
hdb: GCR-8521B, ATAPI CD/DVD-ROM drive
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
hda: attached ide-disk driver.
hda: host protected area => 1
hda: 78165360 sectors (40021 MB) w/2048KiB Cache, CHS=5169/240/63
ide-cd: passing drive hdb to ide-scsi emulation.
hdb: attached ide-scsi driver.
Partition check:
/dev/ide/host0/bus0/target0/lun0: p1 p2 < p5 p6 p7 p8 p9 >
SCSI subsystem driver Revision: 1.00
scsi0 : SCSI host adapter emulation for IDE ATAPI devices
Vendor: HL-DT-ST Model: CD-ROM GCR-8521B Rev: 1.02
Type: CD-ROM ANSI SCSI revision: 02
Attached scsi CD-ROM sr0 at scsi0, channel 0, id 0, lun 0
sr0: scsi3-mmc drive: 52x/52x cd/rw xa/form2 cdda tray
Uniform CD-ROM driver Revision: 3.12
 ************************************************************
  From this I found that My CD-drive is detected as a SCSI device.But what abt my harddisk?.How to find out that my hardisk is detected as a SCSI device.Is there any other way?

3.I am trying to setup a ISCSI SAN in my network.For this the target sud be a SCSI device (as per the doc of iscsi).Is it possible to use my IDE disk for this purpose.??
4.How to findout the LUN of SCSI.can any one explain it briefly.
 Thanks in advance


       
Avatar of jlevie
jlevie

I don't know why both hda=scsi and hdb=scsi are given as boot options since only the CD/DVD device needs or can use ide-scsi  emulation. That's required to be able to use a cdrecord to burn CD's. The hard drive (hda) is operating as an IDE device and that's shown by "hda: attached ide-disk driver" in the dmesg output.

So far as I know to be able to set up an ISCSI SAN you will need a SCSI controller in the system and one or more attached SCSI disks.
Avatar of palanisaravanan

ASKER

well.Thats what i too want to know.Why it passing the value of hda=scsi and if u note down the dmesg
/dev/ide/host0/bus0/target0/lun0: p1 p2 < p5 p6 p7 p8 p9 >
 
  This also means my harddisk only,What this line actually means?>can any one tell me?.I am clueless.
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Avatar of jlevie
jlevie

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