I don't know much about Linux but this actually isn't really a Crystal issue as such, it's more of a Microsoft vs. Linux issue.  There are two pieces to this:  First you'll have to see if there's a SQL Server client available to install on your Linux box.  Then, since Crystal doesn't natively connect to SQL Server, you'll need to determine whether you can use either ODBC or OLE DB on Linux - this will determine what type of connection your report will need to use in order to connect to the database.

We set up a system DSN on the Linux system that houses the Crystal Server. Am able to connect to this DSN from my Crystal Enterprise.

This is how I connect.........used the option ODBC(RDO)to create new connection. Then entered the connection string as DSN=<dsnname>;User Id=<username>;Password=<password>;
I was thus able to map the tables from the SQl Server DB and published the report to the Crystal Server in Linux system.

In the CMC, I set the DB parameters to the option - Use original database logon information from the report. But when I preview the report, it throws an error saying :

"com.crystaldecisions.report.web.viewer.CrystalReportInteractiveViewer
Failed to retrieve initial report values. For example, the database information for this report could be incomplete or incorrect. This is a configuration problem. Please contact your system administrator."

Any ideas, please help. Fix is required asap.

Thanks.