Two RAID 0 questions

[Jeff Vian]

Alexander Dalloz wrote:

>Am Mi, den 25.02.2004 schrieb Allan Metts um 14:46:
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>>At 05:29 AM 2/25/2004, Alexandre Oliva wrote:
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>>>Yes.  IDE doesn't permit simultaneous access to disks on the same
>>>controller.  Well, you could make do with two disks on a single
>>>controller, but performance would be terrible.
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>>Okay, two IDE identical drives -- one will be the Master on the Primary 
>>controller, the other will be the Master on the Secondary controller.
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>>Next question: Will it hurt anything to put the CDROM drive as the Slave on 
>>the secondary controller?  This is a no-no in the SCSI world, since I think 
>>it slows the entire bus down to the speed of the slowest device.  But I 
>>need a CDROM to actually install Fedora, and I'd rather not buy an 
>>additional controller....
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With the newer scsi controllers it is possible to mix devices with 
different speeds on the same bus.

>>Thanks for the help!
>>
>>Allan
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>It's no problem to have a CD-ROM as slave together with a harddrive on
>the same controller. It will not slow down the whole controller.
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Statement 1 is correct
Statement 2 is not.   With IDE busses, all devices on the bus operate at 
the speed of the slowest device.  Thus if you put an ATA133 drive on a 
bus with an ATA33 cdrom, the entire bus only operates at ATA33.   They 
are improving this, and AFAICT the new SATA controllers do not have this 
limitation.


>Alexander
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