I tend to believe (personal opinion and all that crap) that an automatic so=
lution can usually be improved upon by an extremely competent person who kn=
ows the system inside out and all that. Trouble is, there ain 't many peopl=
e like that out there. So for those sites that don 't have Jonathan on a le=
ash, ASM might well be the easiest approach to get reasonable performance. =
Thankfully, there are always going to be those big mothers of systems that=
need someone to hold their hand.
SELECT personal_opinion, witty_remark
FROM company_requirements;
:)
=
Pete
=
"Controlling developers is like herding cats. "
Kevin Loney, Oracle DBA Handbook
=
"Oh no, it 's not. It 's much harder than that! "
Bruce Pihlamae, long-term Oracle DBA
-- --Original Message-- --
From: oracle-l-bounce@(protected) [mailto:oracle-l-bounce@(protected)] =
On Behalf Of Byron Pearce
Sent: Tuesday, 11 May 2004 4:42 AM
To: oracle-l@(protected)
Subject: Re: 10g - ASM
Lisa:
I haven 't run ASM on Windows. Howevever, on Unix platforms it uses the =
raw device, meaning that it has direct access to the disk. In the case =
of your SAN, that would mean the "logical disk " as it is presented to =
the node. In theory, that should be a distinct physical disk but in the =
world of storage virtualization that is not always the case. Having =
said that, if Oracle thinks that two "disks " are distinct and they are =
actually different views of the same physical disk, then this can cause =
ASM to make some poor performance-related decisions regarding its =
striping and mirroring.
I have experimented with it, but haven 't tried to implement it in any =
kind of production capacity. Some of the major arguments put forth for =
the use of ASM include the ability to easily add disks, distribute =
I/O 's, stripe, mirror, etc. all maintained and handled by the database. =
I can see some advantages for the small shops where they want to =
allocate a pool of disks and leave Oracle to run on them without all of =
the disk fine-tuning, but I am not convinced about larger enterprise =
configurations where you 're trying to squeeze every last drop of juice =
out of the lemon. I am still on the fence and haven 't developed a =
religious feeling about it yet as I am still studying the implications.
Hope this helps a bit.
Koivu, Lisa wrote:
>Hello all,=3D20
>
>I 'm currently installing 10g on Windows 2003. Anyone using Automatic
>Storage Management? =3D20
>
>I read this in the ASM documentation (below), and I 'm concerned because
>a LUN is a logical volume. I wonder if implementing ASM is just an
>unnecessary pain for a SAN environment, especially considering the
>enormous SAN cache. =3D20
>
>Way back when I didn 't have grey hair and I worked on Unix, all my
>devices were logical volumes. That was standard in every Unix shop I
>worked in. I get the feeling I 'm missing something or misinterpreting
>this paragraph below. It sounds like it wants direct access to disks,
>period.
>
>I am not a SAN, Unix or Windoze expert. Comments, anyone? =3D20
>
>Thanks
>
>
>
>With Automatic Storage Management, the definition of the logical volumes
>of a storage array is critical to database performance. Automatic
>Storage Management cannot optimize database data placement when the
>storage array disks are subdivided or aggregated. Aggregating and
>subdividing the physical volumes of an array into logical volumes can
>hide the physical disk boundaries from Automatic Storage Management.
>Consequently, careful consideration of storage array configuration is
>required.
>
>
>Lisa Koivu
>Sr. Monkey
>Orlando, FL, USA
>
>
>
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