Subject: Re: ccd on ide drives
To: Jason Downs <>
From: Michael L. VanLoon -- <>
List: current-users
Date: 01/08/1996 20:47:01
>>>I am going to configure the system to support ccd on ide drives. I would
>>>like to know if the ccd supports ide drives and the procedures to do so.
>>>Can anyone share the experience with me. Thanks.

>>Kinda defeats the whole purpose of ccd since IDE doesn't allow for
>>simultaneous transactions on independent drives.  (I. e. IDE makes the
>>transactions serialized, just like not using ccd.)  SCSI allows each
>>drive to operate independently and simultaneosly of the other

>And just *how* does that `defeat the whole purpose' of a *concatenated*

OK, it entirely defeats the performance benefit, one of the two
benefits of ccd.  Semantics aside, just because it's called
"concatenated disks" doesn't mean that's what people primarily use it
for.  My main purpose for going to the trouble of ccd would be to
enhance performance.

My point in writing that was to warn the individual, if he was
thinking about going out and buying another IDE hard drive, he might
want to reconsider spending a little more and moving to SCSI.

If, on the other hand, he already has the drives and simply wants to
make a larger partition, ccd will do that (or should -- I'm not
addressing whether it works correctly over wd devices).  However, it
won't necessarily be any more efficient.

  Michael L. VanLoon                       
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