[CentOS] 3ware disk failure -> hang -- SCSI backplanes

[Bryan J. Smith]

Peter Arremann <loony at loonybin.org> wrote:
> *nods* Have done so - never when working on anything from
> HP, sun or IBM I'v seen anything like what you're
describing...
> SAF-TE is the furthest in that direction but also not even
> close...  
> Ok - so you're referring so saf-te with your above statemts
> or is there more? 

Well, SAF-TE is pretty anal-level, and it's more about
enclosure and other details.  I'd have to fully research
_what_ is exactly required -- at the SCSI card (probably not
much), at the SCSI backplane (probably not much) and at the
SCSI driver (there's the  majority of the beef ;-).

Now, case-in-point/back-to-original-focus:  

3Ware Escalade, Areca ARC and other _true_ hardware ATA cards
are _not_ SCSI-2 cards that provide SCSI-2 feedback to the
kernel.  They have added some capabilities, like smartd and
other daemon support.  But to get the failed/hot-swap
capability, you _must_ let the internal ASIC/microcontroller
-- where _all_ of the "meat" is -- manage the array.

At this point, anyone who doesn't believe what I'm saying can
feel free to assume I'm pulling it all out of rectum. 
Because I've said enough, dissected this all enough and I'm
sure most people who don't care are sick of hearing me try to
explain why you can't use 3Ware cards with software RAID and
handle failures or hot-swap.

And I still want to strangle anyone on the software RAID
lists for continuing to proliferate such.  ;->


-- 
Bryan J. Smith     Professional, Technical Annoyance                      b.j.smith at ieee.org      http://thebs413.blogspot.com
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*** Speed doesn't kill, difference in speed does ***