VxVM allows you to create volumes with the following layout types:
A volume whose subdisks are arranged both sequentially and contiguously within a plex. Concatenation allows a volume to be created from multiple regions of one or more disks if there is not enough space for an entire volume on a single region of a disk.
A volume with data spread evenly across multiple disks. Stripes are equal-sized fragments that are allocated alternately and evenly to the subdisks of a single plex. There must be at least two subdisks in a striped plex, each of which must exist on a different disk. Throughput increases with the number of disks across which a plex is striped. Striping helps to balance I/O load in cases where high traffic areas exist on certain subdisks.
A volume with multiple data plexes that duplicate the information contained in a volume. Although a volume can have a single data plex, at least two are required for true mirroring to provide redundancy of data. For the redundancy to be useful, each of these data plexes should contain disk space from different disks.
A volume that uses striping to spread data and parity evenly across multiple disks in an array. Each stripe contains a parity stripe unit and data stripe units. Parity can be used to reconstruct data if one of the disks fails. In comparison to the performance of striped volumes, write throughput of RAID-5 volumes decreases since parity information needs to be updated each time data is accessed. However, in comparison to mirroring, the use of parity to implement data redundancy reduces the amount of space required.
A volume that is configured as a striped plex and another plex that mirrors the striped one. This requires at least two disks for striping and one or more other disks for mirroring (depending on whether the plex is simple or striped). The advantages of this layout are increased performance by spreading data across multiple disks and redundancy of data.
A volume constructed from other volumes. Non-layered volumes are constructed by mapping their subdisks to VM disks. Layered volumes are constructed by mapping their subdisks to underlying volumes (known as storage volumes), and allow the creation of more complex forms of logical layout. Examples of layered volumes are striped-mirror and concatenated-mirror volumes.
See Layered volumes.
A striped-mirror volume is created by configuring several mirrored volumes as the columns of a striped volume. This layout offers the same benefits as a non-layered mirrored-stripe volume. In addition it provides faster recovery as the failure of single disk does not force an entire striped plex offline.