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SAP and RAC over ServiceGuard...

Luis Angulo
Occasional Contributor

SAP and RAC over ServiceGuard...

Hi everyone...

Does any of you have RAC for SAP running without Serviceguard?

My company has licensed their Oracle databases with SAP, and the license includes the RAC option. We are running our SAP landscape over the HP-UX platform, but we don't have Serviceguard licensed.

I just one to check if any of you have an environment with RAC and SAP over HP-UX without Serviguard (apparently, it seems that at least for SAP is a must to have Serviceguard and SGCFS. Raw and ASM devices are not supported by them).

Thanks in advance,
Luis
4 REPLIES
Volker Borowski
Honored Contributor

Re: SAP and RAC over ServiceGuard...

Hi,

with SAP you'll have a second point of failure to address when HA is considered.
First is of course the database and RAC may help.
But second and not less important is the
SAP Central Instance.

Depending on the SAP release, you might be able to manage a manual setup that does not use a certified HA software and initiate a script based switch to another node, but I guess you might be on unsupported ground then, esp. if you use a j2ee add-in installation.

Check out SAPNET for "HIGH AVAILABILITY" and certified solutions and recomended system setups in this environment.

If you decide to use HA for your SAP system, consider replicated enqueue in addition.

Volker
Duncan Edmonstone
Honored Contributor

Re: SAP and RAC over ServiceGuard...

Luis,

Last time I checked on this (which was admittedly a while ago now), RAC with SAP was still subject to what SAP called "controlled availability" - that is that SAP would want to look at every element of your design (including how and where you were using all SAP modules), and certify your design before providing support dor it. I would certainly check the status of support for RAC with SAP and your HP support contacts before proceeding.

HTH

Duncan

HTH

Duncan
Steven E. Protter
Exalted Contributor

Re: SAP and RAC over ServiceGuard...

Shalom Luis,

apparently, it seems that at least for SAP is a must to have Serviceguard and SGCFS.

>>>
Raw and ASM devices are not supported by them).
<<<

ASM is its own disk management system. It probably does not need Serviceguard but will function properly in an environment managed by SG.

Raw devices not supported by SG? Simply not true.

You can host your database on raw devices either in shared mode (requirement of RAC) or even without RAC in an active passive configuration, using a non-RAC version of the database server.

We here have some Oracle RAC clusters running with only the benefit of Oracles clustering solution. That's 10g and above. the 9g series of Oracle databases requires serviceguard under all configurations.

If SAP requires SG then you need it. Otherwise you may be able to live without it.
As noted above check with SAP support.

I would encourage you to not use SG if its not needed. It is a second, complex cluster system and may not always run nicely and cooperate with Oracle clustering, though the latter was designed to work with SG when needed, but the Oracle people would rather you replaced SG completely.

SEP
Steven E Protter
Owner of ISN Corporation
http://isnamerica.com
http://hpuxconsulting.com
Sponsor: http://hpux.ws
Twitter: http://twitter.com/hpuxlinux
Founder http://newdatacloud.com
Luis Angulo
Occasional Contributor

Re: SAP and RAC over ServiceGuard...

Thanks to everybody for your answers, theyâ re really helpful.

I will double check with SAP the idea of this configuration, either by the fact that it is under â controlled availabilityâ and also, to understand all the restrictions that we have when running SAP over Oracle instead of any other application. It is clear for me that the acquisition of Service Guard + its extension for RAC would be great, mainly because it will help us to protect the SAP Central Instance, but I was trying to take advantage of the fact that the company has RAC already licensed for its SAP environments, and I was trying to get an idea to implement it without a major investment in a complementary clustering solution.

Just to clarify with Steven, when I said that raw devices werenâ t supported I meant with SAP. This is from SAP support:

â A cluster file system (CFS) is a prerequisite for using RAC in the SAP environment. The use of raw devices or those of Automatic Storage Management (ASM) is not supported in the SAP environment.â

Once again, thanks to everyone.
Luis Angulo