Re: asm on san
- From: joel garry <joel-garry@xxxxxxxx>
- Date: Fri, 12 Dec 2008 15:47:30 -0800 (PST)
On Dec 12, 12:09 pm, Mladen Gogala <mgog...@xxxxxxxxx> wrote:
On Thu, 11 Dec 2008 13:16:01 -0800, joel garry wrote:
I have to
admit that it works for my employer, who not only is not doomed but
keeps me busy with expansion projects. Business needs uber alles and
all that. The only time it is a problem is when it is operating in
degraded mode or some rare thing overwhelms the buffering. The more
usual case is akin to a mostly empty municiple bus, plenty of room for
quite a bit more riders. I'd like to take the thanks for that, but
really it's just a reasonable configuration for what it does (ERP/MRP
OLTP, mostly). If I had to choose between Itanium hp-ux RAID-5 and
Itanium Windows RAID-10, I wouldn't pick the Windows.
Joel, I used to share your bias against the Windows boxes but Windows
Server 2008 is actually an excellent OS, with a great shell. It definitely
has a potential. I am not sure whether there is a version of "vi", native
perl installation and some utilities like grep, awk and find, but the OS
holds a promise. It can definitely give Unix a run for its money.
As for RAID 1+0 vs RAID 5 debate, RAID 5 can perform well when equipped
with the copious amounts of NVRAM but that makes it expensive.
Unfortunately, if I give consent to RAID 5, I will probably get a cheapo
version with 2GB of NVRAM and an explanation from the CIO that the sales
person told him that he doesn't need more than that. Low level RAID 1+0
will always beat low level RAID 5, at least in my experience. If you have
enough money for the premium HW, then it doesn't really matter. The small
difference in price will be decided by the current ratio in memory prices
vs. disk prices. You and me both know that RAID 5 must distribute things
over 5 disks, using a complex and compute intensive algorithm. The block
is not written until it's distributed across all 5 disks. That means that
write can only as fast as the slowest of the 5 disks. Granted, ample
memory configuration will alleviate the pain but I am unwilling to rely
on that in case of multi TB databases where a sudden query from Crystal
Reports or Business Objects can attempt to summarize an enormous table
and flush your cache. My experience tells me that RAID 5 usually means
trouble.
--
Interesting you should mention CR, that will be implemented soon.
Long ago when I was an independent contractor I pointed out these same
arguments that you and Dan have made (it is my viewpoint, too), but
the only trouble has been during testing, either hardware bogus enough
to immediately fail or human failings. But it's not multi-TB,
either. And I did mange to get at least the redo on 10, IIRC (don't
have time to check just now, went through several iterations). The CR
and app will be bottlenecked by IIS on W2003r2, I expect. The
analytics are coming from some other MS+3rd party thing on another
W2003 server, I haven't yet seen a problem on the db side, but I don't
think it's being used in anger, either, yet.
When it comes down to it, Cary Millsap is right - you can't prejudge,
you have to look and see. If your users don't have to wait on the
spinning rust, why bother with faster rust? Besides that, sometimes
PHB's guess right, even if for all the wrong reasons, hardware vendors
packages sometimes make sense even if salesmen don't.
So I see 14 actual drives, looking at the thing in the rack. IIRC,
one is unused, one is a hot spare, one is a parity, leaving 11
effective spindles (+IIRC the redo is on internal drives). If it were
RAID-10, wouldn't it be 6 effective spindles? Somehow I don't recall
anyone addressing that, though I might just not remember (or ignored a
RAID-F person...). I know I've pointed out in the past there is a
discontinuity in cost once you fully populate these things. You have
to buy another one, and more controllers, too.
I'm under the impression spindles=performance.
I have a great bias against latest and greatest in production, whether
unix, windows, or oracle, unless demonstrated necessary. But I do
appreciate those who, like you and Dan, check them out and let us
know.
jg
--
@home.com is bogus.
"I just clicked and turned the f/stop. I'm certainly not a
photographer.”
http://www.signonsandiego.com/uniontrib/20081212/news_1m12apollo.html
http://www.microverse.on.ca/cd175/earthrise.jpg
.
- Follow-Ups:
- Re: asm on san
- From: Palooka
- Re: asm on san
- References:
- asm on san
- From: helter skelter
- Re: asm on san
- From: Mladen Gogala
- Re: asm on san
- From: joel garry
- Re: asm on san
- From: Mladen Gogala
- asm on san
- Prev by Date: Re: What will happen after commit statement ?
- Next by Date: Re: Application Server 10g and memory problem
- Previous by thread: Re: asm on san
- Next by thread: Re: asm on san
- Index(es):
Relevant Pages
|
