I set up a usable HA cluster using Oracle standard edition corosync,
pacemaker, and drdb. Note that this was primarily an experiment and I
never tried it under any kind of load. DRBD is a piece of software that
duplicates block by block from source to target. The entire point was to
reduce oracle licensing costs, so the oracle software is dismounted unless
it needs to be running.
https://dbakerber.wordpress.com/2019/03/15/oracle-cluster-with-drbd-pacemaker-and-corosync/
On Sat, Aug 1, 2020 at 8:03 PM Hameed, Amir <Amir.Hameed@xxxxxxxxx> wrote:
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 <oracle-l-bounce@xxxxxxxxxxxxx> *On
Behalf Of *Hameed, Amir
*Sent:* Saturday, August 1, 2020 1:35 PM
*To:* gogala.mladen@xxxxxxxxx; 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 <oracle-l-bounce@xxxxxxxxxxxxx> *On
Behalf Of *Mladen Gogala
*Sent:* Saturday, August 1, 2020 3:51 PM
*To:* 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
