Failover servers must communicate in order to handle resource failover. This is essential for high-availability services. The use of a dedicated heartbeat is a common technique to introduce some intelligence into the failover process. This is often done over a dedicated link (LAN or serial).

Many failover solutions (like Red Hat Cluster Manager and Microsoft Wolfpack) can use a shared SCSI of Fiber Channel disk storage array for failover communication. Information regarding Red Hat high availability solutions for Samba may be obtained from www.redhat.com.

The Linux High Availability project is a resource worthy of consultation if your desire is to build a highly available Samba file server solution. Please consult the home page at www.linux-ha.org/.

Front-end server complexity remains a challenge for high availability because it must deal gracefully with backend failures, while at the same time providing continuity of service to all network clients.