Veritas Storage Foundation™ for Oracle 5.0.1 Graphical User Interface Guide

free space becomes broken into fragments. This means that space must be assigned
to files in smaller and smaller extents. This process is known as fragmentation.
Fragmentation leads to degraded performance and availability. The degree of
fragmentation depends on file system usage and activity.
Fragmentation utilities in VxFS
Allocation units in VxFS are designed to help minimize and control fragmentation.
Over time, however, file systems eventually become fragmented.
VxFS provides online reporting and optimization utilities to enable you to monitor
and defragment a mounted file system. These utilities are accessible through the
file system administration command, fsadm. Using the fsadm command, you can
track and eliminate fragmentation without interrupting user access to the file
system.
Types of fragmentation
VxFS addresses two types of fragmentation:
■ Directory fragmentation
As files are created and removed, gaps are left in directory inodes. This is
known as directory fragmentation. Directory fragmentation causes directory
lookups to become slower.
■ Extent fragmentation
As files are created and removed, the free extent map for an allocation unit
changes from having one large free area to having many smaller free areas.
Extent fragmentation occurs when files cannot be allocated in contiguous
chunks and more extents must be referenced to access a file. In a case of
extreme fragmentation, a file system may have free space that cannot be
allocated.
Starting an Oracle database instance
You can start an Oracle database instance or a cloned Oracle database from the
GUI. You must know the password of the database owner. The steps to restart an
Oracle database instance are the same.
37Managing your database
Starting an Oracle database instance