Are you trying to get us to goad you on raid 5 again Art?

-----Original Message-----
From: owner-informix-list@iiug.org [mailtowner-informix-list@iiug.org]
On Behalf Of Art S. Kagel
Sent: Monday, January 31, 2005 5:51 PM
To: informix-list@iiug.org
Subject: Re: SAN Implementation Questions

Darryl Priest wrote:
> We are considering a SAN implementation and I have a few questions for
> anyone who has already gone through this process.
>
> We are on AIX 5.2 and Informix 9.4. The databases that would reside on
> the SAN would be at least 4 copies of our Elite accounting database at
> about 200 gig each and at least 7 copies of the PeopleSoft database at
> 10 gig each.
>
> Our choices have been narrowed to an HP EVA 5000 or an EMC Clarion
> CX700.
>
> My questions are:
>
> 1.) Does anyone have experience with the HP EVA in conjunction with
> Informix? (I've read the previous SAN related posts but haven't seen
> specific mention of the EVA.)
Not I.

> 2.) Has anyone implemented a SAN with the Elite accounting system?
No.

> 3.) The vendors say it's ok, but, would you mix Windows and Unix data
> on the same drives on the SAN?
I would not put ANY other data on the same devices as my database if
there
are ANY performance requirements at all. You cannot be responsible for
performance of the database server if you have no control over the
resources
it uses. I would isolate the DB disks not only from Windows, but from
all
of the UNIX filesystems, on a separate SAN.

> 4.) Considering the size of our production databases how many
> drives/spindles would be optimum? I know, more is better, but there's
> got to be somewhere that's enough.

Spindles is not your only bottleneck, and yes more is better. Keep in
mind
that it only takes 4 15000 RPM drives to be able to swamp a controller's

ability to keep up with the attached drives' maximum sustained
throughput!
So, not only more spindles but more controller channels as well.

The best rule of thumb I've seen in these days of HUGE singleton drives
is
to calculate the throughput you need, not the storage requirements (GBs
are
cheap after all and expandable), and purchase cabinets/arrays,
controller
channels, and drives to provide that level of throughput peak and
sustained.
Plan to not use more than 30-50% of the available disk capacity (the
outer
30% of the drive return data significantly faster than the inside 1/3 of
the
tracks).

> I'd welcome any general observations or suggestions too.
> Thanks in advance.
>

OH, and remember:

NO RAID5!! NO RAID5!! NO RAID5!! NO RAID5!! NO RAID5!! NO
RAID5!!

Art S. Kagel

sending to informix-list

Mark wrote:
> Are you trying to get us to goad you on raid 5 again Art?

Now why would I do that? Besides when have I ever needed goading to bring
THAT topic up again?

Art S. Kagel

> -----Original Message-----
> From: owner-informix-list@iiug.org [mailtowner-informix-list@iiug.org]
> On Behalf Of Art S. Kagel
> Sent: Monday, January 31, 2005 5:51 PM
> To: informix-list@iiug.org
> Subject: Re: SAN Implementation Questions
<SNIP>

> NO RAID5!! NO RAID5!! NO RAID5!! NO RAID5!! NO RAID5!! NO
> RAID5!!
>
> Art S. Kagel
>
> sending to informix-list