SAP instance startup problem - MCOD

Hi All,

We have installed two SAP systems with MCOD database concept ie.. ERP and CRM system uses single database.

Installation completed successfully...

Now the problem is If I start ERP system first then CRM system will not come up and happening vice versa.

Please suggest me a solution ASAP .How can I distribute the memory to the two instances ..If the problem is not related to the Memory what are all the other things needs to be checked.

Thanks in advance