Implementation of a File System With a Fast and Selective Recovery
Original Publication Date: 1987-Feb-01
Included in the Prior Art Database: 2005-Jan-31
A method is described for facilitating recovery of a file system after storage media failures. The method operates with the shadow page mechanism [*] wherein a mapping is maintained between data pages and their respective storage locations (slots) on disk by having the address (j) of a slot for storing a page stored in one (the kth) of the elements of a vector V. An array M, which contains entries each of which corresponds to a slot, is used to record whether a slot is free. V and M are maintained in recoverable storage. Whenever a page is written into a slot, it is logged into a sequential page log. Each entry in M also contains the address in the sequential page log where the corresponding data page is logged, together with its version number.