NFS

From DreamHost

DreamHost uses NFS to host its accounts. NFS is short for Network FileSystem and basically it means data is not stored on web server machines like a normal computer, but rather the data is stored on a separate machine whose only job is to hold that data. It gives a lot of flexibility, particularly in data recovery and failure procedures (failed webservers can be easily replaced because none of the data is actually on them, for example).