Subject: Re: CCISS support, anyone?
To: Scott Long <>
From: Jonathan Stone <>
List: tech-kern
Date: 03/16/2006 11:25:59
In message <>Scott Long writes
>Jonathan Stone wrote:
>> In message <>,
>> Tonnerre LOMBARD writes:

[rejoin Tonnere's text which I (Jonathang) had split in reply]

>>>But if the support ever broadens - which I hope it will -

[discussion of CISS being publically-available, but a Compaq-internal
standard only, not a real "common" or "standard" interface except
within Compaq/HP ]

>> Other vendors adopt CISS? Huh? Let's think look at that idea for a moment.
>> CISS is a Compaq/HP internal standard, implemented by certain
>> Compaq/HP controllers. Other RAID vendors gain no advantage from
>> adopting this "common" interface. In fact, there are considerable
>> *dis*incentives: CISS is poorly specified, allegedly incomplete, not
>> compatible with any other vendor's existing drivers, installed hw
>> base, or their customers' installed software (driver) base.  Why would
>> any sane engineer at Adaptec or LSI or Mylex drop their existing
>> hardware intefaces, and adopt a Compaq "open standard" instead?
>> Here, I'll quote some comments from the FreeBSD ciss(4) source code:

>The positive side to CISS is that the driver has not needed to change to
>work with newer HPq hardware, even though the spec was released 6 years 
>ago.  The only changes that have been made have been to add features 
>that were already described in the spec, fix driver bugs, and add PCI 
>Ids.  From the perspective of HPq, it is 'common'; they can update their 
>products for newer technologies, and the drivers stay the same.  Yes, 
>there are some ugly parts to the spec, but it also was broad enough 
>allow for future technologies.  Sharply compare that to LSI, Adaptec, 
>3ware, Promise, etc, that have all gone through major driver upheavals 
>in the past 2-3 years.

Yes, sure, but that's all orthogonal to the point I was trying to
make: namely, that CISS was and is a Compaq-internal standard only.
CISS may well be an effective internal standard for Compaq and its
successors; but that's all it is.  Hoping for vendors other than
Compaq and its successors to support CISS is, at best, futile.

I think that we're in agreement on that; do you?

I'd privately emailed a suggested ciss.4 manpage to Tonnere, based on
a mishmash of the FreeBSD and OpenBSD ciss.4 manpages, plus text
specific to netBSD's scsipi subsystem, which said:

	.Cd "ciss* at pci? function ?"
	.Cd "scsibus* at ciss?"
	driver provides support for the CISS interface implemented
	by 5th and 6th generation of the Compaq Smart ARRAY family
	of controllers.

Would it be more accurate to say "fifth and later generations"?
I'm not sure if Tonnere's driver supports all the MSA arrays which the
FreeBSD-6 ciss(4) supports.

[snip Scott's reply to  quoted text written by others]