Planning for Multiple Residency

Running multiple database servers on the same computer is not as efficient as running one database server. You need to balance the advantages of separate database servers against the extra performance cost.

When you plan for multiple residency on a computer, consider the following factors:

• Memory

  Each database server needs its own memory. Can your computer handle the memory usage that an additional database server requires?

• Storage space

  Each database server must have its unique storage space. You cannot use the same disk space for more than one instance of a database server. When you prepare an additional database server, you must repeat some of the planning that you did to install the first database server. For example, consider these questions:

  • Will you use buffered or unbuffered files? Will the unbuffered files share a disk partition with another application? (For more information on buffered and unbuffered files, see the section on direct disk access in the IBM Informix: Administrator's Guide.)
  • Will you use mirroring? Where will the mirrors reside?
  • Where will the message log reside?
  • Can you dedicate a tape drive to this database server for its logical logs?
  • What kind of backups will you perform?