Is it possible to install two SAP system with same SID but different instance numbers on one host?

[Former Member]

Is it possible to install two SAP system with same system ID (SID) but different instance numbers on one host?

If yes, then how?

If no, then why?

Thanks in advance.

Regards,

Sarim

[Former Member · Accepted solution]

If you are talking about multiple whole systems (central instances) I think the answer is, yes you can. At least, from the SAP viewpoint. How? Just specify the required instance numbers during installation. You may have an issue with the database however. I'm not sure you can install two Oracle DBs on the same host with the same SID. Other DB systems may not have this problem. If it is an issue, you could have one or both DBs on different hosts, or maybe you could have the SAP SID and the DB SID not be the same?

I am curious about why you'd want to do this...

If you are talking just about multiple instances of the same system, rather than multiple whole systems, then it is much more straightforward, and in fact isn't unusual. I've had systems set up this way in the past.

[Former Member · Accepted solution]

Thanks a lot Steve,

I asked this question out of curiosity and because of some implications I could think of installing two systems with same SID. (Like pointed out by Reagon below):

- What would happen if i switch user to <sid>adm and give "stopsap" on console?

- There is a messege server service called sapms<SID> to which a port is assigned in /etc/services file, if I make two entries for sapms<SID> with different port numbers, how will the system know that which is the external port for calling messege server of which system?

Regards,

Sarim

[Former Member · Accepted solution]

stopsap takes an optional profie parameter specifying the system to stop. By default it stops DVEBMGS00, but you can specify an alternative profile.

The /etc/services file might actually be a problem. You can't have two different entries for sapms<SID>. That said, there's a profile parameter rdisp/msserv that contains the service name to use, so maybe the second one could be "sapms<SID>2" ? I've never tried that, so I've no idea if it would work.

In these days of virtualisation, there's no really need to worry about this sort of thing. If you need to run two systems with the same SID on the same hardware, put at least one of them in a virtual container and all these problems go away.Running multiple systems on the same server, even with different SIDs, is a hack from a different decade. Don't do it:-)

Steve.

[Former Member]

Why would you do something against recommendations from SAP? See the attached screenshot from the installation guide. <SID> is included in file system directories as well as database configuration, network port mappings, etc. Simply, don't do it. Spend your energy and time elsewhere.

[Reagan]

Is it possible to install two SAP system with same system ID (SID) but different instance numbers on one host?

Yes, it is possible. If one is CI (PAS) and the second one is an AS (AAS). In this case there will be only one database.

If you are talking about two separate SAP systems with separate databases (Eg: A BI and an ECC) with the same SID then the problem will be with the database (Eg: Oracle)

The database will be installed under /oracle/SID/112_64 (ORACLE_HOME) unless one database is running on 10 G and in that case the ORACLE_HOME will be /oracle/SID/102_64

The next issue will be with the SAP file systems like /sapmnt/SID

The most important problem will be with the switch to the sidadm and orasid users and the conflicts there. If there is a need to stop one of the SAP systems and if you do a switch to sidadm and issue a stopsap command which system will be stopped ?

These are few of the many problems I can think of.

So if we are talking about two separate systems with their own databases I would rule out the possibility of having two systems with the same SID.

Regards

RB

[Former Member]

Thanks Reagon,

These were the exact reasons which prompted me ask this questions.

Regards,

Sarim

[madasamy_arunachalam]

Hi

Again, it is depends on type of products (systems)  ?

For MDM, SAP has specific note.. ...."to install another set of servers please install them under a different SID"

Ref. : 1531460 - An MDM SID should contain only one of each of the servers

regards

Swami

[Matt_Fraser]

During an upgrade, the shadow system installed by the upgrade process is just this:  a system with the same SID but different instance number.  Per Steve's point, in this case both systems share the same database, so there isn't really an issue with database naming.  SQL Server has a concept called MCOD (Multiple Components One Database), which does allow installing multiple independent SAP systems to a single database (each with its own schema).  It looks like DB2 supports this, as well.