<P> Appliance based devices are dedicated hardware devices that provide SAN connectivity of one form or another . These sit between the hosts and storage and in the case of in - band ( symmetric ) appliances can provide all of the benefits and services discussed in this article . I / O requests are targeted at the appliance itself , which performs the meta - data mapping before redirecting the I / O by sending its own I / O request to the underlying storage . The in - band appliance can also provide caching of data , and most implementations provide some form of clustering of individual appliances to maintain an atomic view of the metadata as well as cache data . </P>
what will be used by san to provide connectivity between hosts and storage
Appliance based devices