Re: Migrate from AIX to Linux
Date: Fri, 18 Dec 2015 11:16:33 +0100
Message-ID: <CAEogZXWJ6YD7fOxOE5eSqFoZENdOjY-fHoHZAnuEHrCcmwr_2Q_at_mail.gmail.com>
In case you use a more recent version of Veritas on Linux (e.g. 6.2.x), you can use the CIO option as well.
# man mount_vxfs
...
...
cio Mounts the file system for concurrent reads and
writes. Concurrent I/O (CIO) offers performance benefits
for well-behaved major commercial databases via
mechanisms of unlocking and unbuffering. Only these
databases and other applications that do not need
POSIX concurrency guarantees should use CIO.
The cio option cannot be disabled by remounting
the file system. To disable the cio option, unmount the
file system, then mount the file system without the
cio option.
Cheers,
William
On Thu, Dec 17, 2015 at 9:34 PM, Deepak Sharma <dmarc-noreply_at_freelists.org> wrote:
> 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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> http://www.freelists.org/webpage/oracle-l
>
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>
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>
-- http://www.freelists.org/webpage/oracle-lReceived on Fri Dec 18 2015 - 11:16:33 CET