Re: Migrate from AIX to Linux

From: Andrew Kerber <andrew.kerber_at_gmail.com>
Date: Thu, 17 Dec 2015 15:07:32 -0600
Message-ID: <CAJvnOJY0Ky40GOEwVzy4whpw+ecZHKOzbsVX_Q9r+zNLGk=LBQ_at_mail.gmail.com>

asynch and direct io. If there is some reason why you do not want to use ASM, use filesystemIO_options=setall in the init.ora.

On Thu, Dec 17, 2015 at 3:00 PM, Dimensional DBA < dimensional.dba_at_comcast.net> wrote:

> CIO is redundant to Oracle overall I/O and caching mechanisms. You should
> use Oracle ASM on Linux.
>
>
>
>
>
> *Matthew Parker*
>
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> *From:* oracle-l-bounce_at_freelists.org [mailto:
> oracle-l-bounce_at_freelists.org] *On Behalf Of *Deepak Sharma (Redacted
> sender "sharmakdeep_oracle" for DMARC)
> *Sent:* Thursday, December 17, 2015 12:35 PM
> *To:* andrew.kerber_at_gmail.com; gogala.mladen_at_gmail.com;
> oracle.blog3_at_gmail.com
>
> *Cc:* oracle-l_at_freelists.org
> *Subject:* Re: Migrate from AIX to Linux
>
>
>
> We are still ways out before we implement the solution (several months),
> but will definitely keep posted.
>
>
>
> I had a kind of related question w.r.t. AIX vs Redhat Linux. Currently we
> use CIO with AIX. Is there anything equivalent on Linux (that doesn't
> involve ASM)?
>
>
>
> On Thursday, December 17, 2015 12:48 PM, Andrew Kerber <
> andrew.kerber_at_gmail.com> wrote:
>
>
>
> I am interested to hear how it goes, and how many rehearsals you plan
> before the final go live.
>
>
> -----Original Message-----
> From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org]
> On Behalf Of Mladen Gogala
> Sent: Thursday, December 17, 2015 12:17 PM
> To: Deepak Sharma; oracle.blog3_at_gmail.com
> Cc: oracle-l_at_freelists.org
> Subject: Re: Migrate from AIX to Linux
>
> On 12/17/2015 12:52 PM, Deepak Sharma wrote:
> > Now, since you have experience with actually doing the migration, let
> > me know if this would work (we will of course try it out soon too):
> >
> > 1. Copy the 'datafile copies' from source to destination staging area
> This can be achieved with a minimal downtime, by shutting down the
> database and snapping LUNs which contain the database. That is equivalent
> to a cold backup, only two orders of magnitude faster. After the snapshot,
> the database can be restarted.
>
>
> > 2. Run the 'convert from platform' RMAN command, to convert those
> > datafile copies so they land in the real datafile locations
>
> Mount the snapshot onto the target machines and run "rman convert" to real
> locations. Re-create the control file with the new file locations.
> Since the target is Linux RAC, those will most probably look like this:
> '+DATA/<db_unique_name>/datafiles/......'. Something like "vi" with
> global string replace capability would be ideal for editing "create
> controlfile" statement.
>
> > 3. Copy the subsequent 'Incrementals' from source to destination area
>
> Everything else remains the same. And yes, I have done that.
>
> > 4. Convert the Incrementals on destination to apply to real datafile
> > (from Step 2).
> > 5. Repeat 3 & 4, until you're almost caught up, and do a final 3 & 4
> > with source tablespaces being read-only.
> >
> > Does this make sense? Pls share your thoughts.
> Yes it does. However, few steps have been left out. I am not sure whether
> AIX db is single instance or RAC, but you will need to add the undo
> tablespace for each instance and create as many redo threads as you have
> instances. Single-instance database has only a single active redo thread.
> You will also need to add instances to OCR by using srvctl add instance.
> Only when that is done, you will have a full fledged RAC database on Linux.
>
> Also, be very careful when performing loads. Make sure that the same
> tables are only loaded from one machine. Good luck, may the force be with
> you.
> Regards
>
> >
> > -thanks
> >
>
>
> --
> Mladen Gogala
> Oracle DBA
> http://mgogala.freehostia.com
>
>
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-- 
Andrew W. Kerber

'If at first you dont succeed, dont take up skydiving.'

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Received on Thu Dec 17 2015 - 22:07:32 CET