To help optimize performance for different types of volumes, VxVM lets you set one of several read policies on data plexes.

Figure: Use of mirroring and striping for improved performance shows an example in which the read policy of the mirrored-stripe volume labeled Hot Vol is set to prefer for the striped plex PL1.

The prefer policy distributes the load when reading across the otherwise lightly-used disks in PL1, as opposed to the single disk in plex PL2. (HotVol is an example of a mirrored-stripe volume in which one data plex is striped and the other data plex is concatenated.)

To improve performance for read-intensive workloads, you can attach up to 32 data plexes to the same volume. However, this approach is usually an ineffective use of disk space for the gain in read performance.