You use metadevices to increase storage capacity and data availability. In some instances, metadevices can also increase I/O performance. Functionally, metadevices behave the same way as slices. Because metadevices look like slices, they are transparent to end users, applications, and file systems. Like physical devices, metadevices are accessed through block or raw device names. The metadevice name changes, depending on whether the block or raw device is used. See "Metadevice Conventions" for details about metadevice names.
You can use most file systems commands (mount(1M), umount(1M), ufsdump(1M), ufsrestore(1M),and so forth) on metadevices. You cannot use the format(1M) command, however. You can read, write, and copy files to and from a metadevice, as long as you have a file system mounted on the metadevice.
SPARC and x86 systems can create metadevices on the following disk drives:
SPARC - IPI, SCSI devices, and SPARCStorage Array drives
x86 - SCSI and IDE devices