[CentOS] New controller card issues

Thu May 28 22:02:37 UTC 2015
Valeri Galtsev <galtsev at kicp.uchicago.edu>

On Thu, May 28, 2015 4:25 pm, Gordon Messmer wrote:
> On 05/28/2015 11:13 AM, Valeri Galtsev wrote:
>>
>> I do not want to start "software" vs "hardware" RAID wars here
>
> I'm not saying that hardware RAID is bad, entirely.  Software RAID does
> have some advantages over hardware RAID, but my point has been that
> 3ware cards, specifically, are less reliable than software RAID, in my
> experience.

If I get you correctly you are saying that 3ware RAID cards are prone to
hardware failures - as opposed to software RAID which is not (as it does
not include hardware, so never has a hardware failures), right? No this is
a joke of course. But it's the one one asked for ;-)

Now, seriously: of more than a couple of dozens of cards I used during
last about 13 years not a single one died on me. Still I do not consider
myself lucky. I also do not have specifically excellent conditions in a
server room. Just ordinary ones. Sometimes during air conditioning
maintenance temperature in the server room is higher than in our offices
(once we has 96F for a couple of hours, of course this was a unique case.
BTW during these 2 hours none of AMD based boxes got sick. But a few Intel
ones did). So, I have no special conditions for our equipment. Boxes are
behind APC UPSes, that's true, but that is sort of nothing special. I also
probably should mention that all 3ware cards I used were bought new, never
used by someone else. Couple of dozens is decently representative
selection statistically, so I probably can't just claim myself lucky. I'm
still convinced that 3ware RAID cards _ARE_ reliable.

Again, I don't know your statistics: i.e. how many did you use, how many
of them died (failed as hardware). How well surge-free the power is. How
well the guys who installed your cards into your boxes followed static
discharge precautions (yes, even though these cards are robust, one may
fry them slightly by static discharge, and they may fail - as many fried
ICs they not always fail right away, but some time later, say, in a year;
still as a result of static discharge). To be fair, I'm often not wearing
that anti-static bracelet, but I do touch metal tars of the box,
anti-static bag the card ships in etc - which is sufficient IMHO.

So, still not considering myself lucky, yet never having 3ware card die on
me (out of over couple of dozens, during over 13 years, and most of the
cards are in service for some 8-10 years since they originally were
installed). In my book 3ware RAID cards are reliable hardware.

Valeri

++++++++++++++++++++++++++++++++++++++++
Valeri Galtsev
Sr System Administrator
Department of Astronomy and Astrophysics
Kavli Institute for Cosmological Physics
University of Chicago
Phone: 773-702-4247
++++++++++++++++++++++++++++++++++++++++