TRIM support through ciss

[Dmitry Morozovsky]

On Wed, 5 Jun 2013, Jeremy Chadwick wrote:

[snip a bit]

> I assume this is you running stable/9 with r251419 or newer (which just
> got committed a few hours ago)?

Yes, sure, I missed to mention it explicitely.

> I haven't looked at the code, but it is very, VERY important to remember
> that you are *always* at the whim of 1) the controller driver (ciss(4)
> in this case), and 2) the controller firmware, as to whether or not
> certain pass-through commands are supported (in this case, since you
> have a SAS controller, this would be accomplished via a SCSI command
> that your controller does not support.

I tried to chase versions, and it seems I use for this Proliant the last set.

> Oh, it looks like Steve just replied and said more or less what I did.
> :-)
> 
> Bottom line as "we" (the royal we, I guess) have been saying for many
> years now: any controller which operates in a RAID fashion and does not
> support "true JBOD" (meaning the controller acts a generic controller
> with no concept of RAID), will almost always get in the way.  Instead,
> stick with true non-RAID controllers -- and yes I am aware choices are
> limited.

well, the server in question "has been fallen from the heaven", ya know ;-)
if I were the builder, I suppose I'd use SuperMicro platform + non-RAID LSI 
HBA...

on the other hand, battery-backed cache...

not an easy choice, yes.

-- 
Sincerely,
D.Marck                                     [DM5020, MCK-RIPE, DM3-RIPN]
[ FreeBSD committer:                                 marck at FreeBSD.org ]
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*** Dmitry Morozovsky --- D.Marck --- Wild Woozle --- marck at rinet.ru ***
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