Top-down volume creation enables you to automatically create Solaris Volume Manager volume configurations using the metassist command. You no longer need to manually go through the process of partitioning disks, creating RAID-0 volumes (as submirrors), creating hot spare pools and hot spares, and finally creating a mirror. Instead, you can issue the metassist command to create a volume. Solaris Volume Manager does the rest for you.
The metassist command enables you to create Solaris Volume Manager volume configurations with a single command. You can specify volume characteristics in terms of quality-of-service. Quality-of-service characteristics means that without specifying the hardware components to be used in a volume, you can use input to the metassist command to provide the following:
Level of redundancy, which refers to the number of copies of the data
Number of data paths to the volume
Fault recovery, which indicates whether the volume is associated with a hot spare pool
You can specify the volume by quality-of-service with command-line options or in an input file named on the command line.
In some cases, it is important to more specifically define the volume characteristics or the constraints under which the volumes should be created. In such cases, you can also specify the following characteristics:
Volume types (for example, a RAID-0 (concatenation) or RAID-0 (stripe) volume).
Components to use in specific volumes.
Components that are available or unavailable for use.
Number of components to use.
Details specific to the type of volume being created. Details include the stripes, the read policy for mirrors, and similar characteristics.
If you prefer to specify the names, sizes, and components of a volume in more detail, use an input file. Input files include volume request files and volume specification files. For more information on how to use input files, see Top-Down Volume Creation Processes.
Finally, you can constrain the metassist command to use (or not use) specific disks or paths.