How to move upgraded SPS sites under one site collection in MOSS - sharing single Content Database?

Category: Common Problems faced during Upgrade from SPS2003 to MOSS2007

Problem:
How to migrate 2 or more site collections from SPS to MOSS – under one site collection and wherein the migrated site collections should share the same content DB?

Scenario:
In SPS 2003, there is only one content database and in MOSS we want a separate content database for each site collection.

HR and IT are two site collections in SPS.
http://SPSprod/sites/IT & http://SPSprod/sites/HR
In MOSS, we want to migrate this under one site collection CORP i.e. http://MOSSprod/CORP/IT & http://MOSSprod/CORP/HR. Our aim is to get one content database for CORP. HR and IT will reside under CORP and will share the same Content database.

For getting data specific to HR and IT only from SPS2003 database, we used STSADM

STSADM.exe –o backup http://SPSprod/sites/IT -filename backup_IT.bak
STSADM.exe –o backup http://SPSprod/sites/HR -filename backup_HR.bak

Solution:
Create the site collection ‘CORP’ under web application ‘MOSSprod’. As MOSSprod already has one more site collection, we needed to create a separate content DB for CORP. For that I followed the below steps:

1) Go to MOSS Central Administration à Go to Application Management à Click on Content Databases under SharePoint web application management à Click on MOSSprod’s content DB and ‘Manage Content database settings’ page appears. Make MOSSprod’s content DB OFFLINE.

2) Create a new content database and put 15000 or any larger no in Maximum number of Sites column. Make sure the sum between “Current number of Sites” and “Maximum number of Sites” is the largest in the Content database you want to use before you run the stsadm – restore command.

3) Create site collection ‘CORP’ under MOSSprod web application. In our case, we did it through STSADM. We restored the migrated sites from SPS2003 to MOSSprod such that all sites under CORP use one content DB.

Stsadm.exe –o restore http://MOSSprod/CORP/ -filename backup_IT.bak
Stsadm.exe –o restore http://MOSSprod/CORP/ -filename backup_HR.bak

As the MOSSprod original content DB is offline, system sees the new content DB which is available and restores the data there.