Introduction to Solaris Volume Manager
Solaris Volume Manager is a software product that lets you manage large numbers
of disks and the data on those disks. Although there are many ways
to use Solaris Volume Manager, most tasks include the following:
Increasing storage capacity
Increasing data availability
Easing administration of large storage devices
In some instances, Solaris Volume Manager can also improve I/O performance.
For information on the types of disks supported in the Solaris operating system,
see Chapter 11, Managing Disks (Overview), in System Administration Guide: Devices and File Systems.
How Solaris Volume Manager Manages Storage
Solaris Volume Manager uses virtual disks to manage physical disks and their associated
data. In Solaris Volume Manager, a virtual disk is called a volume. For
historical reasons, some command-line utilities also refer to a volume as a metadevice.
From the perspective of an application or a file system, a volume
is functionally identical to a physical disk. Solaris Volume Manager converts I/O requests directed
at a volume into I/O requests to the underlying member disks.
Solaris Volume Manager volumes are built from disk slices or from other Solaris
Volume Manager volumes. An easy way to build volumes is to use the
graphical user interface (GUI) that is built into the Solaris Management Console. The
Enhanced Storage tool within the Solaris Management Console presents you with a
view of all the existing volumes. By following the steps in wizards, you
can easily build any kind of Solaris Volume Manager volume or component. You
can also build and modify volumes by using Solaris Volume Manager command-line utilities.
For example, if you need more storage capacity as a single volume,
you could use Solaris Volume Manager to make the system treat a collection
of slices as one larger volume. After you create a volume from these
slices, you can immediately begin using the volume just as you would use
any “real” slice or device.
For a more detailed discussion of volumes, see Overview of Volumes.
Solaris Volume Manager can increase the reliability and availability of data by using
RAID-1 (mirror) volumes and RAID-5 volumes. Solaris Volume Manager hot spares can provide
another level of data availability for mirrors and RAID-5 volumes.
Once you have set up your configuration, you can use the Enhanced
Storage tool within the Solaris Management Console to report on its operation.