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macdba321 - 28 Apr 2008 15:26 GMT

Hi all,
I'm setting up my first ASM based database ever. (Just for testing
and learning, NOT for production). I only have 3 physical disks in the
ASM disk group. (4 total physical disks in the server).

I am loading the OS (Windows 2003 server) on one physical disk as
well as the Oracle installation. I am keeping the other 3 disks raw
for ASM.

Should I RAID the 3 raw disks (hardware RAID and/or Oracle raid) or
just let Oracle do what it wants with them?

Thanks!

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hpuxrac - 28 Apr 2008 17:45 GMT

> Hi all,
> I'm setting up my first ASM based database ever. (Just for testing
[quoted text clipped - 9 lines]
>
> Thanks!

What most people do in the real world ( the ones actually using ASM
anyhow ... not a large percent yet of the oracle installed base ) is
basically this.

If your storage environment supports RAID well then they get LUNs from
it and define the ( LUNs become disks in an ASM diskgroup ) diskgroup
as external redundancy.

This tells ASM hey don't bother doing any overhead of mirroring the
extents you allocate across disks ... my storage environment does a
nice job of dealing with that stuff.

If the storage environment doesn't support RAID then they point ASM at
disks and let ASM do the mirroring, You have a choice of 2 or 3 way
mirroring to add additional protection levels.

So all in all this design is up to you ... perhaps it should be based
on the type of testing that you want to do and how that relates to an
eventual production environment that you might be running in
eventually.

There's a book that you might want to think about getting "Oracle
Automatic Storage Management" it's one of those Oracle Press books
authors are Vengurlekar, Vallath and Long includes 10g and 11g.
Personally I recommend getting and reading that book ( it really isn't
that long ) and spending a day or 2 reading it before you make more
decisions about your setup.

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kwlewin@gmail.com - 28 Apr 2008 18:07 GMT

Thanks for the reply. I actually just got the exact book you
recommended. Since I (for once) have time on my hands, I'm taking the
approach of getting my feet damp and playing around with it for a week
or so and then reading the book to make it "make sense" when I read
about feature X, Y, or Z (since I may have seen it then). Somewhat
backwards approach I realize, but with a server and time on my hands,
it works for me! :)

That being said, a simple question:

If you wanted to build a server that has only 4 physical hard
drivers and have ZERO need for HA or redundancy (data loss in the
event of a drive crash is OK!), you just want to configure a server
for 100% maximum speed ..... how would you set it up?

A) Hardware-based RAID-0 across the 3 disks and control them via ASM
B) Oracle-based RAID-0 across the 3 disks and control them via ASM
C) No RAID and control them via ASM
D) Other?

Thanks for the input!

> > Hi all,
> > I'm setting up my first ASM based database ever. (Just for testing
[quoted text clipped - 37 lines]
> that long ) and spending a day or 2 reading it before you make more
> decisions about your setup.

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macdba321 - 28 Apr 2008 18:18 GMT

Thanks for the reply! I actually just got the book you recommended and
since (for once) I have some spare time and some spare hardware, I'm
playing around with it as I read along.

Regardless, since this is all 100% for fun/academic, a quick question:

If you were setting up a server/database for 100% speed (ie, ZERO
requirements for HA and/or disaster recovery .....if I lose a drive,
oh well, I start over, etc.):
(The server has 3 raw disks)
Would you:

A) Hardware-based RAID-0 the 3 disks and let ASM see them afterwards
as 1 "device"
B) Oracle-based RAID-0 the 3 disks
C) Don't use RAID at all
D) Other????

Thanks, and again, this is 100% academic/fun .... this is ZERO
requirement for High Avail!!!!!!!!!!!!!!!!!!!!!!

Thanks!

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hpuxrac - 29 Apr 2008 00:27 GMT

snip

> Thanks for the reply! I actually just got the book you recommended and
> since (for once) I have some spare time and some spare hardware, I'm
> playing around with it as I read along.

The book is pretty good. Definitely written by the people that
designed the software.

> Regardless, since this is all 100% for fun/academic, a quick question:
>
[quoted text clipped - 12 lines]
> Thanks, and again, this is 100% academic/fun .... this is ZERO
> requirement for High Avail!!!!!!!!!!!!!!!!!!!!!!

Vladimir has a good point about the online logs. You can isolate them
on 1 disk ... either an ASM disk or file system based ( if you were
running unix/linux then a direct raw partition is one option ) ... you
can in other words mix and match some parts of the database asm but
others not.

For the other 2 disks why not lie to asm and tell them they are
external redundancy. So create a diskgroup that has just those 2 disk
as external redundancy. Now when you create tablespaces on it asm
will alternate extents between the 2 disks. In other words, you can
use raid 0 to stripe or you can view them as 2 disks and let asm do
that part.

What you really need is about 7 (or more) disks. Use 2 for the online
logs in archive log mode so when you write to one, you then switch
logs, write to the other while the first online log is being archived
to disk 3. Then setup disks 4, 5, 6, 7 as disks in an external
redundancy log group but just allocate part of the disks ( outer
cylinders ) for best IO performance. ( Take your server admin out to
lunch ... by them an itunes gift certificate and bingo ... more
hardware appears eh? ).

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macdba321 - 28 Apr 2008 18:39 GMT

Hello, apologies if you receive this reply twice (It didn't reply
successfully the 1st time).

I just got the book you recommended and am playing with the database
server as I go along for fun (since for once I have time on my hands).

The database server has 3 raw disks for me to "play" with.

This is 100% academic/fun. There is ZERO need for High Availability/
redundancy. If I lose a drive, oh well, I start over. It doesn't
matter.

One quick question:

If you wanted to set it up for 100% performance/speed, would you:

A) Hardware-based RAID-0 the 3 raw disks as 1 ASM disk group,
B) Oracle-based RAID-0 the 3 raw disks for ASM
C) Some other RAID level?
D) Other???

Thanks!!!!!!!

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Vladimir M. Zakharychev - 28 Apr 2008 19:57 GMT

> > > Hi all,
> > > I'm setting up my first ASM based database ever. (Just for testing
[quoted text clipped - 60 lines]
>
> Thanks!!!!!!!

I'd do D): one spindle for ASM DG1 dedicated for redo logs and
possibly a copy of control file (yes, it's going to be tremendous
waste of space, but you wanted speed, didn't you? ;) and two spindles
striped with hardware RAID-0 for ASM DG2, where the database (in
NOARCHIVELOG mode!) and flash recovery area would be. Both disk groups
would be with external redundancy to minimize mirroring overheads;
separate spindle dedicated for redo should minimize the i/o component
of redo log sync times. This setup automatically offers zero data
protection as requested. :)

My $0.02,
Vladimir M. Zakharychev
N-Networks, makers of Dynamic PSP(tm)
http://www.dynamicpsp.com

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macdba321 - 28 Apr 2008 21:35 GMT

On Apr 28, 2:57 pm, "Vladimir M. Zakharychev"
<vladimir.zakharyc...@gmail.com> wrote:

> > > > Hi all,
> > > > I'm setting up my first ASM based database ever. (Just for testing
[quoted text clipped - 75 lines]
> N-Networks, makers of Dynamic PSP(tm)
> http://www.dynamicpsp.com

Thank you. I was starting to have the exact same though as you. (1 ASM
group comprising 1 disk for redologs & control + 1 ASM group
comprising 2 disks for datafiles and flash.)
Seems like the fastest possible setup.

What I don't know however is if the 4 disk share 1 controller, 2
controllers, etc??

I guess regardless, that must be the fastest setup!

Thanks again. Any other thoughts??

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macdba321 - 28 Apr 2008 18:45 GMT

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macdba321 - 28 Apr 2008 18:54 GMT

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