On 17/02/2011 01:45, Stan Hoeppner wrote:
David Brown put forth on 2/16/2011 6:26 PM:
On 17/02/11 00:32, Stan Hoeppner wrote:
RAID level space/cost efficiency from a TCO standpoint is largely irrelevant
today due to the low price of mech drives. Using the SATABeast as an example,
the cost per TB of a 20TB RAID 10 is roughly $1600/TB and a 20TB RAID 6 is about
$1200/TB. Given all the advantages of RAID 10 over RAID 6 the 33% premium is
more than worth it.
I don't think it is fair to give general rules like that. In this particular
The IT press does it every day. CTOs read those articles. In many cases it's
their primary source of information. Speak in terms CTOs (i.e. those holding
the purse) understand.
I work at a small company - I get to read the articles, make the
recommendations, and build the servers. So I can put more emphasis on
what I think is technically the best solution for us, rather than what
sounds good in the press. Of course, the other side of the coin is that
being a small company with modest server needs, I don't get to play with
20 TB raid systems!
case, that might be how the sums work out. But in other cases, using RAID 10
instead of RAID 6 might mean stepping up in chassis or controller size and
costs. Also remember that RAID 10 is not better than RAID 6 in every way - a
RAID 6 array will survive any two failed drives, while with RAID 10 an unlucky
pairing of failed drives will bring down the whole raid. Different applications
require different balances here.
I'm not sure about being "fair" but it directly relates to the original question
that started this thread. The OP wanted performance and space with a preference
for performance. This demonstrates he can get the performance for a ~33% cost
premium. He didn't mention a budget limit, only that most vendor figures were
too high.
I agree that RAID 10 sounds like a match for the OP. All I am saying is
that it is not necessarily the best choice in general, and not just
because of the initial purchase price.
Also, you're repeating points I've made in this (and other) threads back to me.
Try to keep up David. ;)
I'm doing my best! I believe I've got a fair understanding of various
sorts of RAID systems, but I am totally missing real-world experience of
anything more advanced than a four disk setup. Bigger raid setups is
only a hobby interest for me at the moment, so I'm learning as I go
here. And you write such a lot here that it's hard for an amateur to
take it all in :-)
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