Hi Riaan,
Thank for your excelent explanation!
Now I know I'll have to run an Oracle unsupported environment ... :)
Would someone please confirm if the environment suggested by Hirantha is
supported by Red Hat?
* 2 GFS/RAC nodes;
* 2 DLM on RAC/GFS nodes;
* fibre channel external storage.
The above environment is what we usually encounter on our cluster
projects. Sometimes Oracle Database is installed as active-passive (not
a RAC Cluster). It would be useful to know if Red Hat supports it, even
if Oracle does not.
Last question: does Oracle supports a 2-node cluster using DLM for
Oracle Database (no RAC, no GFS) when used with RHCS?
Thanks again!
Celso.
Riaan van Niekerk escreveu:
hi Hirantha
short answer: "No"
If you are willing to settle for "should work just fine" instead of
"certified by Oracle" you can try running DLM on 2 RAC/GFS nodes, then
"yes"
To have your solution certified/supported by Oracle, for a minimal
configuration you need 5 machines:
a) 2 GFS/RAC nodes
b) 3 external GULM lock servers
We also found these system requirements somewhat excessive (having more
lock servers than actual GFS-accessing cluster nodes).
more notes:
- supported GFS with RAC is GULM only - DLM is not supported by Oracle,
because it is embedded by default.
- external lock servers - that means the the GULM service cannot run on
the nodes accessing the GFS. The 3 GULM nodes and the 2 GFS/RAC nodes
must be completely separate
- the reason for the separation of lock servers from GFS/RAC nodes is
that Oracle RAC is designed to be able to with a single node up, whereas
DLM needs a quorum of 50%+1 to operate. Also, external lock servers
allow you to reboot any RAC node without causing the lock server to switch.
- specs for the locks servers are as entry-level as you can get for
modern server hardware, e.g. 1CPU, 1GB RAM.
- Red Hat Knowledge base article for RAC on GFS:
http://kbase.redhat.com/faq/FAQ_78_3853.shtm
It mentions GFS 6.0, (slightly out of date) but is just as relevant for
GFS 6.1 / RHEL 4). According to this article, "Red Hat does not charge
for Red Hat GFS nodes that are used only for the external lock server
configuration"
- the Cluster/GFS FAQ has some URLs for RAC on GFS:
http://sources.redhat.com/cluster/faq.html#gfs_oraclerac
- MetaLink Note 329530.1 is the definitive source for what exactly is
supported by Oracle, w.r.t. RAC and GFS. Unfortunately it is only
available via Metalink.
Celso - answers to your questions below
...
--
*Celso Kopp Webber*
celso@xxxxxxxxxxxxxxxx <mailto:celso@xxxxxxxxxxxxxxxx>
*Webbertek - Opensource Knowledge*
(41) 8813-1919
(41) 3284-3035
--
Linux-cluster mailing list
Linux-cluster@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/linux-cluster
