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:
1. VMotion is not an HA solution even though VMWare white papers on
Oracle clearly call their solution HA
2. Using the F5 appliance to reroute connections in the event the
database server becomes unavailable and this is their preferred HA solution
citing the following links:
https://www.f5.com/pdf/solution-center/f5-oracle-database.pdf
https://www.f5.com/pdf/deployment-guides/oracle-rac-database-dg.pdf
https://www.f5.com/content/dam/f5/corp/global/pdf/white-papers/load-balancing-oracle-database-wp.pdf
https://www.oracle.com/technetwork/middleware/beehive/overview/maa-wp-beehive-f5-bestpractices-129874.pdf
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,
Amir
________________________________
From: Mladen Gogala <gogala.mladen@xxxxxxxxx>
Sent: Saturday, August 1, 2020 7:10 PM
To: Hameed, Amir <Amir.Hameed@xxxxxxxxx>; oracle-l@xxxxxxxxxxxxx
Subject: Re: Oracle database HA on VMWare without using RAC
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
From: dimensional.dba@xxxxxxxxxxx <dimensional.dba@xxxxxxxxxxx>
Sent: Saturday, August 1, 2020 6:59 PM
To: Hameed, Amir <Amir.Hameed@xxxxxxxxx>; gogala.mladen@xxxxxxxxx;
oracle-l@xxxxxxxxxxxxx
Subject: RE: Oracle database HA on VMWare without using RAC
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@xxxxxxxxxxxxx<mailto:oracle-l-bounce@xxxxxxxxxxxxx>
<oracle-l-bounce@xxxxxxxxxxxxx<mailto:oracle-l-bounce@xxxxxxxxxxxxx>> On Behalf
Of Hameed, Amir
Sent: Saturday, August 1, 2020 1:35 PM
To: gogala.mladen@xxxxxxxxx<mailto:gogala.mladen@xxxxxxxxx>;
oracle-l@xxxxxxxxxxxxx<mailto:oracle-l@xxxxxxxxxxxxx>
Subject: RE: Oracle database HA on VMWare without using RAC
Thanks Mladen!
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.
Thanks
From: oracle-l-bounce@xxxxxxxxxxxxx<mailto:oracle-l-bounce@xxxxxxxxxxxxx>
<oracle-l-bounce@xxxxxxxxxxxxx<mailto:oracle-l-bounce@xxxxxxxxxxxxx>> On Behalf
Of Mladen Gogala
Sent: Saturday, August 1, 2020 3:51 PM
To: oracle-l@xxxxxxxxxxxxx<mailto:oracle-l@xxxxxxxxxxxxx>
Subject: Re: Oracle database HA on VMWare without using RAC
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:
Hi,
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
