Re: Data Mirroring on two data centers -- How to use ASM ?
- From: Madhu V <db.mail.1@xxxxxxxxx>
- To: "Goulet, Dick" <DGoulet@xxxxxxxx>
- Date: Thu, 18 May 2006 14:29:15 -0500
Thank You both !!
*Mirroring:*
Unfortunately, I am dealing w/ AIX here (although I would prefer Linux).
Idea here is to mirror data across TWO data centers while using ASM. In
this particular test we won't be using GPFS (CFS). Most of the
documentation out there refers mainly to raw devices. So I am under the
impression that, use AIX volume manager to deal with the LUNS mirrored
across two data centers and all i need is simple raw devices and
ownership changed to Oracle:dba to be able to use by ASM (external
redundancy). So if i am correct, we are using AIX volume manager along
w/ ASM (external redundancy)... _*Please correct me if i am wrong*_
Secondly, i think this should be another possibility... assign the LUNS
(from both the data centers) to ASM instance and create failure groups
to mirror the data across two data centers... but we will have to
careful in choosing the LUNS for each failure group to make sure the
data is mirrored. In this scenario, there is no use of AIX volume
manager, but ASM will mirror the data.. again please correct me if i am
wrong w/ advises.
if at all, the above are possible, which is one is best and why?
*Striping:*
Dick, would you please confirm _/turning off striping/_ , I am under the
impression that Mirroring can be external, but ASM does striping and no
way to stop it.
Thank You,
Madhu
Goulet, Dick wrote:
Madhu,
I'm not sure if you can use AIX Volume manager with ASM. I doubt
it. I did my RAC install on RedHat so used the Oracle cluster
software, cluster ready services I believe it is called. It installed
very nicely so I would want to do the same thing next time as well.
As for striping, if you don't want ASM to do the striping for you,
like I did not, you can choose to have that managed externally. It's
a simple check box in the installer.
------------------------------------------------------------------------
*From:* oracle-l-bounce@xxxxxxxxxxxxx
[mailto:oracle-l-bounce@xxxxxxxxxxxxx] *On Behalf Of *Madhu V
*Sent:* Thursday, May 18, 2006 2:00 PM
*To:* oracle-l@xxxxxxxxxxxxx
*Subject:* Data Mirroring on two data centers -- How to use ASM ?
Hello All,
We are planning on testing a two node 10g RAC using ASM for one of our
database on pSeries using AIX 5.3. We have a primary requirement of
mirroring data across TWO data centers (Hitachi SAN). I have two
questions
1. Mirroring.
Can we use AIX Volume Manager to take care of the mirroring or ASM
to do mirroring. I am specifically looking for HOW and WHY?
2. Striping
I have seen a similar post just a few days ago on ASM striping,
although i couldn't understand much of it (Pardon my knowledge on disk
technologies). Our storage folks told me that, they have a huge disk
cache (128 GB) and very high performing SAN (HDS 9980) w/ excellent
algorithm for striping the LUNS across multiple disks. So HOW best I
can use ASM striping along w/ HDS storage striping? or will it cause
any performance problems??
Please advise me...
Good Day,
Madhu
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