Multihosted Data

The logical host's disksets are multihosted so that when a physical host crashes, one of the surviving hosts can access the disk. For a data service to be highly available, its data must be highly available, and thus its data must reside on the logical host's diskset.

A data service might have command-line switches or configuration files pointing to the location of the data files. If the data service uses hard-wired path names, it might be possible to change the path name to a symbolic link that points to a file in the logical host's diskset, without changing the data service code. See Appendix A, Using Symbolic Links for Multihosted Data Placement, for a more detailed discussion about using symbolic links.

In the worst case, the data service's code must be modified to provide some mechanism for pointing to the actual data location. You can do this by implementing additional command-line switches.

Sun Cluster supports the use of UFS, VxFS, and raw partitions on the logical host's diskset. When the system administrator installs and configures Sun Cluster, he or she must specify which disk resources to use for UFS or VxFS file systems and which for raw partitions. Typically, raw partitions are used only by database servers and multimedia servers.