Browse Prior Art Database

Recoverable Delay-Write Caching for Network File Server

IP.com Disclosure Number: IPCOM000120962D
Original Publication Date: 1991-Jun-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 1 page(s) / 53K

Publishing Venue

IBM

Related People

Kirkpatrick, ES: AUTHOR [+3]

Abstract

Disclosed is a fully recoverable delay-write caching design for network servers using either the local client disks or battery-powered RAM devices in diskless client nodes.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 75% of the total text.

Recoverable Delay-Write Caching for Network File Server

      Disclosed is a fully recoverable delay-write caching design for
network servers using either the local client disks or
battery-powered RAM devices in diskless client nodes.

      When a client node issues "write" request, data blocks are
transferred to network servers through the communication channel.  At
the same time, the client file system stores the data to a local
client disk for back-up purpose.  The server cache then performs the
delay-write operation on these data without requiring a disk access
for each request. Once the cached data have been written to the
server disk, invalidation signals are sent back to the clients to
clear out the corresponding backup data blocks on the client disks.
To maintain data integrity on multiple writes of correlated data from
different clients, the server cache needs to commit to the most
recent write and invalidate other backup writes before continuing its
operation.  If the server loses some cached data due to a sudden
power failure, all back-up data blocks at client nodes are
transferred to the server disk to avoid system crash.

      For network diskless client nodes, battery-powered RAM devices
can be used to support the back-up function.  In addition, while data
are being held in local RAM caches during the server delay-write
operation, the following "read" requests from each client are
processed through its local cache.  A cache hit can then elim...