SAP ECC 6.0 EHP5 installation on MSCS Windows 2008 R2

[Former Member]

Dear Gurus,

I am about to start my first SAP installation on MSCS Windows 2008 R2 for product ECC 6.0 EHP 5.

I have already downloaded the installation guide and read the section HA installation multiple times.

Few queries I have for you to please discuss and help, Before starting the installation of DATABASE, shall all the sap cluster groups and DB groups be made at  cluster level ?

Like for DB -> DBGroup

            SAP -> SAPGroup

Do I need to creates the users like SIDADM or SERVICESID manually or shall they be created automatically ?

I do have a hint that Using new IM for EHP5 users are created automatically , but still would like to be assured.

Also , if you can confirm the sequence below is right for installation ?

1. DB installk on first node

2. DB install on 2nd node

3. Follow thw installation sequence on the SAP IM.

additionally, when DB is installed and it asks me for location of Datafile and Logfiles, shall it be shared SAN device or the local hard disk ?

Thanks a lot in advance for sharing spirit.

Cheers !

Shobhit

[former_member192421 · Accepted solution]

Hi Shobhit,

SAP installer takes care of this activity.
During installation at the 2nd stage, the installer will ask for the password for OS users <SID>adm & sapservice<SID> & for database users 'sys' & 'system' also.

and for sap user creation, you have to do it manually.

After installation by default you will get two sap users SAP* & DDIC.

I hope this helps...

Regards,

Rajkumar

[Former Member · Accepted solution]

Dear Rajkumar,

Are we talking about MSCS cluster ? I know in normal installation SAPINST creates SIDADM and SERVICESID user automatically, but in case os MSCSC also is it the same case ??

Cheers !

Shobhit

[Former Member · Accepted solution]

Hello Gurus,

I figured out that Users are getting created automatically by the SAPINST.

I have one more doubt -

Installation guide says :

8.4.7Installing the Dialog Instance

You have to install at least one dialog instance for MSCS. You have the following options to install the dialog instance.

Why is it comulsory to install the dialog instance?

My plan of action was :

First cluster node installation : at Node 1

Database instance : at Node 1

Additional cluster node : at Node 2

Primary app server instance : at Node 2

So, is this correct? Is installing dialog instance here is mandatory ? Am I missing out something ?

Cheers !

Shobhit

[Former Member · Accepted solution]

Hi,

Can anyone please confirm me if in Windows 2008 R2 MSCS , the central instance on node 1 and dialog instance on node 2 have same instance number?

Regards,

Shobhit

[Former Member · Accepted solution]

Hi Shobit,

If you mean the same database instance by the same instance then yes they have the same instance 🙂

Coming to your earlier question about why atleast 1 dialog instance is must is kinda simple if you follow the standard SAP design/architecture for HA. In HA all instances (except ASCS and SCS and even ERS) reside locally as in disks and in case of failures don't failover. So suppose you have only 1 central instance (actual term is primary application server) running on any node and if that node fails your only App server is gone. Which means no dispatcher which means users can't connect. HA is useless in that case.

So that is why you need another app server !

Regards.

Ruchit

[Former Member · Accepted solution]

HI Ruchit,

Thanks for wonderful explanation ! You made it pretty clear now.

So just to confirm this means I will have to keep the same instance number (00) for both CI and dialog instance and they installed on different nodes of cluster ?

Regards,

Shobhit

[Former Member · Accepted solution]

Hi Shobhit,

Theoratically I think it is possible. Two different hosts i.e hostnames i.e profile names would be different. Also the instance names would be different i.e DVEBMGS00 and D00. The instance directories would reside on local disks in this case so no conflict there. So I can't see why it is not possible. However practically speaking I SAPinst would not probably allow this. I have never tried this and would never suggest doing it.

Moot question is why do it. Why not seperate everything neatly. I would never do it and hence would never recommend it.

These kind of things can hit you back at times. So my recommendation would be to use different instance numbers for every single instance. So please use different instance numbers. It is free of cost 🙂

Further in my earlier post I mentioned even ERS is on local disk. I would like to elaborate a little on that. This is strictly your choice. In case of bi-nodal cluster when ASCS fails over to ERS (say node 1 is down and node 2 is up) you would bring down ERS on node 2. When node 1 appears back if you go for failback then ERS can be started again on node 2 and in this case ERS can be on local disk. If however you don't go for failback and want to start ERS on node 1 then you need ERS on node 1 but that scenario would rarely happen since you won't want node 2 to be loaded with DB,secondary app and ASCS also.

If however you have multi-nodal cluster then I would strongly recommend to have ERS on shared disks so that you can keep ERS on any node.

Regards.

Ruchit.

[Former Member · Accepted solution]

Hi Ruchit,

The reason why I am planning to keep it as same is ....my MSCS will act as active-passive, so sapgroup and dbgroup both will run on Node 1 in normal situation.

Now suppose node 1 goes down , DBBGROUP will failover to node 2 and sapgroup will also failover.

If I have the same instance number for CI and DI, then atleast users will not get disconnected as failover is hardly for few seconds.

But if the instance number is different, users will get disconnected and will have to login again.

So does this makes valid reason ? Looking forward for yoiur reply to be clearified please.

Regards,

Shobhit

[Former Member · Accepted solution]

Hi  Shobit,

Sorry didn't understand it clearly. However  users don't just get connected to an instance number (i.e dispatcher port)  they also specify host name. It is the host and port combination. Now you would say that hostname being used is virtual host but it won't be normally for primary app server else you are planning to put primary app also in the cluster.

Regards.

Ruchit.

[Former Member · Accepted solution]

Hi Ruchit,

Thanks, your statement do makes a lot of sense !!

So does that means even in cluster, if one node is down and failover occurs then users will mandatororily get disconnected momentarily and have to log in again??

Is there any option to avoid this situation in MSCS may be using Logon groups or something ?

Also, according to below forum, Alberto replied that if CI and DI are kept same users are not getting disconnected, what are your views on it  ?

http://scn.sap.com/thread/2013094

Regards,

Shobhit

[Former Member · Accepted solution]

Hi Shobit,

Don't agree with this really (Alberto's POV) since for me this defies tcp/ip packet adddress concept (hostname:port). I don't think it works they way it is assumed. May be no user was logged onto the application server running on the node that has failed. In that case no disconnect would happen. What if all users are connecting to app server directly instead of message server..in that case it makes sense.

I rather agree with Sunil Kumar Ravindran has to state here (though would like to make an addition). In case of DB instance failover reconnect isn't a necessity since you can control that with DB recon parameters. But restart of WPs happens. 

http://scn.sap.com/thread/1084650

Having said I have never implemented this kind of solution but I don't think it is gonna work. I mean if app server I am logged into goes down I won't get redirected to another app server automatically. Even with logon load balancing it won't work since that is just an entry point. Eventually message server redirects all incoming requests to individual dispatchers.

But may be other community memeber have a different view point which might help you. As I said in all my HA experiences I have never implemented this scenario (and probably never would since I don't think it will work 🙂 )

Regards.

Ruchit.

[Former Member · Accepted solution]

Hello all,

Below are the instances I chose, and everything is working perfectly fine.

ASCS                    00    shared

CI                           01    local

ERS on node 1     10     local

DI                           01    local

ERS on node 2     10     local

Cheers !

Shobhit

[Former Member · Accepted solution]

Hi Shobhit,

Congratulation...

Can you please conclude this.

CI installation performed on Node 1.

DI installation performed on Node 2.

During fail over from node 1 to node 2,

no user get disconnected which are connected with CI which is on node1.

Regards,

Nikunj Thaker

[Former Member · Accepted solution]

Hi Nikunj,

Yes I can confirm that no users are getting disconnected.

Cheers,

Shobhit

[devinder_abap]

Hi Experts,

Can Anyone please tell me, if I can install ECC 6 on windows 8 (64Bit)? If yes, kindly send me the steps, if anyone can arrange.

Thanks
Devinder

[Former Member]

Hi SHobhit,

For the disks datafiles and log files - please see the section Distribution of SAP System Components to Disks for MSCS...

For SAP Group - it can be done with MSCS SAP INST on the first node.

For DB group - Execution of MSCS wizard or database-specific cluster scripts

For user creations .. You have an option in SAP Inst -> software life cycle management -> Create operating system users... You can run that in both the nodes...

All the info has been given in the guide. Please go thru it again.

Thanks,

Jagadish.

[Former Member]

Hi Jagadish,

Thanks for the info, I have read the guide and everything is almost explained very clearly like howto and whereto.

But my question was not on how to configure SAP group and DB Group and USERS.

I want to know before starting the SAP installation, do OS team make SAP and DB group themselves while configuring cluster or will SAPINST take care of it while the SAP installation on WINDOWS 2008 R2.

Also will the users be automatically get created as in normal SAP instalation or will I have to create the users manually ?

Cheers !!

Shobhit