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Administration Guide

Considerations for Table Spaces

You must decide on the type of table space that you want to use. If you want to use SMS table spaces, you must set them up using disks from the disk groups that belong to a logical host. In addition, you must include them in the vfstab for the logical host. Refer to the Sun Cluster 2.1 documentation for information about how to add a file system to a logical host.

There are benefits and costs associated with using either SMS or DMS table spaces. For example, SMS table spaces reside on file systems that must be file-system checked before they are mounted. This can add a considerable amount of overhead when failover occurs, and can result in the Sun Cluster 2.1 software timing out. If you use SMS table spaces, ensure that they are journaled file systems, which require less time to check after a failover.

DMS table spaces that use raw devices do not have to be file-system checked during failover. This can reduce the failover time for the high availability scripts, but you should remember that committed transactions that are written to the logs will be applied to the database during crash recovery after the database server fails over.

If you are using raw devices for table spaces (that is, you are using DMS table spaces), you must ensure that the disks are part of the disk group of the logical host.

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