difference between scsi and fc

[isha_82]

can any one help me in telling the difference between scsi and fc harddisks

[Peter Godron]

Hi,
not disks, but transfer medium !
See:
http://www.backupbook.com/05Hard_Drives/AASCSI_Basics.html
or any other number of sources (wikipedia)

[IT_2007]

As for as you won't see any difference for the disks unless you are interested in IO.

[Jaime Bolanos Rojas.]

isha,

Some people said there are fc disks, but in reality they are not, this the case specially when using EVAs.
Looks like the disk is connected trough fc, but it's actually first connected to scsi at the back of the harddrive and then goes into FC, making FC disks non existant.

Regards,

Jaime.

[Steven E. Protter]

Shalom,

Note that though different, FC behaves like SCSI and has SCSI ID's which must not conflict.

ioscan picks them up just like scsi disks.

SEP

[Uwe Zessin]

> Some people said there are fc disks, but in
> reality they are not, this the case specially
> when using EVAs.

The reality is that the EVA does use FC disk drives.

> Looks like the disk is connected trough fc,

They _are_ connected through FC.

> but it's actually first connected to scsi
> at the back of the harddrive

Wrong.
Today's "SCSI disks" have an 80-pin connector which provides power and all signals for a parallel-SCSI interface.
"FC disks" have a 40-pin connector which provides power and two FC_AL (Fibre Channel Arbitrated Loop) ports.

> and then goes into FC, making FC disks non existant.

--

When somebody is talking about "SCSI", usually the traditional 'electrical parallel SCSI bus' is meant.

Fibre Channel can carry multiple protocols. In the case of storage, the unfortunate naming of "Fibre Channel Protocol" (FCP) is used, but this is nothing else than a mapping of "serial SCSI" onto a FC infrastructure.

[NMory]

Links Difference SCSI and FC protocols:

http://searchstorage.techtarget.com/ateQuestionNResponse/0,289625,sid5_cid524082_tax294583,00.html

http://searchstorage.techtarget.com/tip/0,289483,sid5_gci1145276,00.html

LN

[Jaime Bolanos Rojas.]

Uwe,

You must be totally right on everything that you said, but like Galileo said once,
Until I do not see the FC cable coming out of that drive, it does not matter if it's 80 pin or 40 pin, it will be a scsi drive.

Regards,

Jaime.