Re: Migrate from AIX to Linux

From: Mladen Gogala <gogala.mladen_at_gmail.com>
Date: Tue, 23 Feb 2016 06:45:03 -0500
Message-ID: <56CC463F.4070400_at_gmail.com>

Sorry, I have never used RAT. Cannot say anything.

On 2/22/2016 11:14 PM, Oracle List wrote:
> Thanks for the feedback.
>
> Switching gears a little. How's Oracle RAT in that sense comparatively
> ? If we keep cost aside would that be able to closely mimic the
> workload and replay it on the target?
>
> On Feb 22, 2016, at 9:25 PM, Mladen Gogala <gogala.mladen_at_gmail.com
> <mailto:gogala.mladen_at_gmail.com>> wrote:
>
>> SLOB is a generic benchmark that imitates a generic database load,
>> not necessarily your database load. The output it produces could be
>> useful in addition to the other, more complex tools. HammerOra and
>> Swingbench are tools that I have some experience with. Both tools can
>> be used to execute a pre-defined mix of transactions that you will
>> have to tailor yourself to reflect your database use. It's been about
>> 5 years since I've used HammerOra for the last time, but it was
>> fairly easy to use and did the job. Make sure that the workload you
>> generate using any of those tools closely resemble the workload of
>> your application. Make sure that you measure IO capabilities of your
>> new configuration accurately. PowerPC minicomputers really shine when
>> it comes to IO, you would need to craft your configuration very,
>> very carefully if you wish your generic Linux boxes to match your AIX
>> box IO capabilities. You will probably need some rather expensive
>> toys like Dell XtremIO.
>>
>> On 2/22/2016 2:42 PM, Deepak Sharma (Redacted sender
>> sharmakdeep_oracle for DMARC) wrote:
>>> In preparation for the migration from AIX to Linux, we are starting
>>> to look into tools to compare performance between the two environments.
>>>
>>> To recap, this is a 170TB DB, generating 5TB archive a day (even
>>> after a lot of operations as nologging).
>>>
>>> What are some 'low-cost good-quality' tools that you can recommend
>>> (or have an experience with), to compare performance before we
>>> cut-over to Linux?
>>>
>>> The Oracle's Real Application testing (RAT) is an option but could
>>> be very expensive. I have also read about BenchMark factory,
>>> HammerOra, JMeter, SwingBench and SLOB. Any thoughts?
>>>
>>> Thanks,
>>> Deepak
>>>
>>>
>>> On Thursday, December 17, 2015 3:08 PM, Andrew Kerber
>>> <andrew.kerber_at_gmail.com> wrote:
>>>
>>>
>>> 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 <mailto: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*
>>> *Chief Technologist*
>>> *425-891-7934 (cell)*
>>> *Dimensional.dba_at_comcast.net*
>>> *View Matthew Parker's profile on LinkedIn*
>>> <http://www.linkedin.com/pub/matthew-parker/6/51b/944/>
>>> *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
>>> <mailto:gogala.mladen_at_gmail.com>; oracle.blog3_at_gmail.com
>>> <mailto: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
>>>
>>>
>>> --
>>> http://www.freelists.org/webpage/oracle-l
>>>
>>>
>>>
>>> --
>>> http://www.freelists.org/webpage/oracle-l
>>>
>>>
>>>
>>>
>>> --
>>> Andrew W. Kerber
>>>
>>> 'If at first you dont succeed, dont take up skydiving.'
>>>
>>>
>>
>> --
>> --
>> Mladen Gogala
>> Oracle Consultant
>> http://mgogala.freehostia.com
>>
>> DISCLAIMER: I am solely responsible for any opinion expressed in this email

-- 
--
Mladen Gogala
Oracle Consultant
http://mgogala.freehostia.com

DISCLAIMER: I am solely responsible for any opinion expressed in this email


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Received on Tue Feb 23 2016 - 12:45:03 CET