RE: Oracle database HA on VMWare without using RAC
Date: Sun, 2 Aug 2020 01:01:27 +0000
Message-ID: <DM6PR11MB3483FFFFFC81EA38E5A5363FF44C0_at_DM6PR11MB3483.namprd11.prod.outlook.com>
Thank you all who have replied to my mail.
We are preparing a list of HA options (RAC, GG, etc.) along with their costs and then let the business decide how much it is willing to spend. From my experience, I have seen that the business would initially say that it would need 24x7 with absolutely no downtime for their application but then as soon as they look at the cost of that solution (for example, RAC.), their requirement change and a few hours of downtime would be acceptable!
In this particular case, I am dealing with so-called system architects whose definition of HA doesn't include the database layer. For example, I am being told consistently that:
What they are not able to comprehend is that even if F5 is able to reroute application connections in no time to another database host running Oracle standby database, it would take some amount of time to activate the standby database into the primary role and during that time, the application will not be available to users.
The oracle-list has some of the brightest minds who work on all sorts of technologies and I wanted to find out if VMotion is a viable option to recover from situations where the underlying ESX host of a VM running Oracle DB fails and what the kind of outage to expect for the time it takes to relocate that VM to another ESX host.
Thanks,
Hi Amir!
I am primarily a DBA. That is my background. I am not a system administrator or a storage administrator, I don't configure or monitor any of this stuff. However, VMotion promises "zero downtime" which is not possible with Oracle. The fabled bitmaps in VMotion are the same as Oracle's change tracking device for incremental backups: it tracks changed blocks and it does sort of VM snapshot on the fly. It can be a good solution if you move your machine to another host while the database is down. I wouldn't try it with a running DB.
Regards
I have used VMotion at a variety of clients for low level fail over's meaning scheduled maintenance, but don't try to VMotion when the database is under heavy load.
It doesn't protect you for an HA perspective if the OS/Oracle SW becomes corrupted or your database is corrupted or hard down.
From: oracle-l-bounce_at_freelists.org<mailto:oracle-l-bounce_at_freelists.org> <oracle-l-bounce_at_freelists.org<mailto:oracle-l-bounce_at_freelists.org>> On Behalf Of Hameed, Amir
Sent: Saturday, August 1, 2020 1:35 PM
Thanks Mladen!
Thanks
Standby database or Golden Gate are rather usual options. Other than that, you can setup a Veritas failover cluster for VMWare:
https://www.veritas.com/content/support/en_US/doc/ka6f10000000CAjAAM
You can do the same thing using MSFT cluster:
https://docs.vmware.com/en/VMware-vSphere/6.0/vsphere-esxi-vcenter-server-601-setup-mscs.pdf
There is also VMWare HA:
https://www.vmware.com/pdf/vmware_ha_wp.pdf
Last, but definitely not least, there is Commvault Live Sync for VMWare. It's sort of standby for VMWare.
https://documentation.commvault.com/commvault/v11/article?p=106002.htm
Virtual machines are disk files. Fail-over clusters move the disk drive to the surviving node and restart the service. There are also hardware based solutions on remote disk replication. Every major SAN vendor (EMC, Hitachi, NetApp) has remote disk replication software, usually for the high end arrays and usually separately licensed. What kind of money are you looking to spend? What is the acceptable switch-over time? Are you looking for the software-only solution, hardware solution or the combination of both? Here is a good article about VMWare high availability:
https://www.nakivo.com/blog/vm-failover-guide/
This is a question for a system architect within your company. The most important question is how much do you want to spend? When you have the $$$ then it's basically testing various commercial solutions, some of which are listed above.
On 7/31/20 11:08 PM, Hameed, Amir wrote:
Amir
From: Mladen Gogala <gogala.mladen_at_gmail.com>
Sent: Saturday, August 1, 2020 7:10 PM
To: Hameed, Amir <Amir.Hameed_at_xerox.com>; oracle-l_at_freelists.org
Subject: Re: Oracle database HA on VMWare without using RAC
From: dimensional.dba_at_comcast.net <dimensional.dba_at_comcast.net>
Sent: Saturday, August 1, 2020 6:59 PM
To: Hameed, Amir <Amir.Hameed_at_xerox.com>; gogala.mladen_at_gmail.com; oracle-l_at_freelists.org
Subject: RE: Oracle database HA on VMWare without using RAC
To: gogala.mladen_at_gmail.com<mailto:gogala.mladen_at_gmail.com>; oracle-l_at_freelists.org<mailto:oracle-l_at_freelists.org>
Subject: RE: Oracle database HA on VMWare without using RAC
Have you had any experience with using VMWare's VMotion feature to provide HA to Oracle databases? We are looking for a cost effective way to provide HA to an Oracle database. RAC, Veritas, GG are all excellent but expensive options. What I don't know is how effective VMotion is in minimizing the outage time for Oracle databases.
From: oracle-l-bounce_at_freelists.org<mailto:oracle-l-bounce_at_freelists.org> <oracle-l-bounce_at_freelists.org<mailto:oracle-l-bounce_at_freelists.org>> On Behalf Of Mladen Gogala
Sent: Saturday, August 1, 2020 3:51 PM
To: oracle-l_at_freelists.org<mailto:oracle-l_at_freelists.org>
Subject: Re: Oracle database HA on VMWare without using RAC
I am looking for options/features available in VMWare to provide high-availability to single-instance Oracle databases. If anyone is using VMWare to provide HA solution to their Oracle database, I would appreciate if I could be pointed to the right direction.
Thank you,
Amir
--
Mladen Gogala
Database Consultant
Tel: (347) 321-1217
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http://www.freelists.org/webpage/oracle-l
Received on Sun Aug 02 2020 - 03:01:27 CEST