Re: Upgrading Oracle cluster 11gR2 on Solaris
From: Mladen Gogala <gogala.mladen_at_gmail.com>
Date: Fri, 22 Jan 2016 02:11:41 -0500
Message-ID: <56A1D62D.3070608_at_gmail.com>
On 01/20/2016 05:12 PM, Ali Alizadeh wrote:
> Hello
>
> We are planning to upgrade our oracle cluster 11.2.0.3 using raw
> device (no ASM) to oracle GI 12c/ASM.
> What will be the best approached to minimize the downtime?
>
> Regards,
> Ali
>
Well, if you have to upgrade on the same machine, then you don't have any choice: since 12c doesn't support raw devices. you will have to reformat them and put them into an ASM. That is a looong downtime because that generally means expdp/impdp. However, if you can get yourself a new set of machines, then the procedure is much simpler:
Date: Fri, 22 Jan 2016 02:11:41 -0500
Message-ID: <56A1D62D.3070608_at_gmail.com>
On 01/20/2016 05:12 PM, Ali Alizadeh wrote:
> Hello
>
> We are planning to upgrade our oracle cluster 11.2.0.3 using raw
> device (no ASM) to oracle GI 12c/ASM.
> What will be the best approached to minimize the downtime?
>
> Regards,
> Ali
>
Well, if you have to upgrade on the same machine, then you don't have any choice: since 12c doesn't support raw devices. you will have to reformat them and put them into an ASM. That is a looong downtime because that generally means expdp/impdp. However, if you can get yourself a new set of machines, then the procedure is much simpler:
- Create Grid infrastructure 12c and create a single instance 11G standby on that box.
- Install Oracle 12c on one of the new boxes (software only).
- Fail over the to the standby. The downtime begins.
- Upgrade newly minted 11G database to 12c using DBUA.
- Make the new database into a RAC: you should already have UNDO tablespaces and redo threads, just configure the instances and add them OCR using srvctl add instance -i <SID> ....
- Bring the newly minted 12c RAC up. Downtime ends. The duration of downtime depends on how long does it take to convert the DB and how fast you can make it RAC. You can make several attempts, because breaking the link between the primary and standby doesn't necessarily mean downtime. If your infrastructure is good (10GB LAN or better), you can relatively easy create standby database from the live database.
However, cost of the downtime in the era of the Internet and web based economy can be exorbitant. I am sure that your employer will gladly buy relatively cheap generic hardware and avoid potentially devastating downtime. I know of a case where downtime was measured as $100.000 per hour. For large companies like Netflix, Amazon, Ebay, Paypal, banks with on-line banking and stores like Walmart, the cost of total downtime is probably much higher than that. And $100.000 can buy a lot of generic PC hardware.
-- Mladen Gogala Oracle DBA http://mgogala.freehostia.com -- http://www.freelists.org/webpage/oracle-lReceived on Fri Jan 22 2016 - 08:11:41 CET