Difference between SID and instance number

[Former Member]

Hi,

Can you please tell me the difference between SID and Instance number.

Can one SID have any no if instance.But i think u can have only one SCS.Please explain

[Former Member]

Hi Naveen,

SID is System Identifier it is used to Identify Uniquely in the Landscape

Instance Number is to dentify Uniquely in the SID

The SID should be Only one to the System

But Each SID can have 00 to 96 (97,98,99 not used for us) Instances's

if you see the SM51

Server Names : <HOSTNAME>_<SID>_<INSTANCE NO>

Thanks & Regards,

Kishore Reddy

TCS,Chennai.

[Former Member]

This message was moderated.

[Former Member]

See my below message

null

[Former Member]

Try Transaction code --> <b>AL08</b> ...You can see the all the instance with users logged in each instances.

Try T-Code <b>SM04</b> for users logged in the your logged in instance.

Thanks,

Sam

[Former Member]

You only have a single SID (system ID) per System and can have multiple instance numbers per SID -

For example - we have a central instance and an application server on our QA System

SID = QA1

Instance number 00 for Central Instance and 01 for Application server

Our Production system's SID is PR1 and we have 00, 01 and 02 as instance numbers!

[Former Member]

Hi Barry, can you help me with this question:

I have development system with sid DEV and instance number for example 05. I want to install another develop. system for migration/system copy. Can this new system have the same sid: DEV - like real develop. system?? Instance number can be for example 06.

I don't want that test system somehow mess up real dev system because they have same SID. Both system will be on same domain. Thanks.

[Former Member]

they can have the same SID, however should be

- installed on seperate hardware (otherwise they will colide on OS level)

- not be connected to eachother (via RFC, http, TMS, etc.).

- should use local users instead of domain users (if this is Windows environment)

So it can be done, but please be carefull.

[Former Member]

Hi Barry,

From your explanation what i understood is :

Sap products like SRM, CRM, R/3 etc. will have their individual unique SIDs while the instances (both central and other instances) will have their respective instance numbers.

am i correct?

Regards,

Dinesh.