Browse Prior Art Database

AFS Initialization Performance Enhancement

IP.com Disclosure Number: IPCOM000108534D
Original Publication Date: 1992-Jun-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 2 page(s) / 61K

Publishing Venue

IBM

Related People

Lucas, JC: AUTHOR [+3]

Abstract

Disclosed is a method to improve the Andrew File System (AFS) Cache Manager start-up time in an OS/2* environment. This enhancement focuses on the data file verification in the data cache subdirectory.

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This is the abbreviated version, containing approximately 54% of the total text.

AFS Initialization Performance Enhancement

       Disclosed is a method to improve the Andrew File System
(AFS) Cache Manager start-up time in an OS/2* environment.  This
enhancement focuses on the data file verification in the data cache
subdirectory.

      In a distributed file system, such as AFS, remote file data
(i.e.,  at a server) is cached locally at the client. In the AFS case
the file data is cached on disk in fixed length data cache files.  At
start-up time, it is possible to have valid, up-to-date data in a
given cache file (i.e., the data has not been updated in any way at
the server) from the last time the remote file was accessed.  With
this in mind, it is important not to discard the data cache file when
initializing the AFS client.

      The data cache filenames are built into a globally shared table
at initialization time based on the number of files the user has
configured.  This can be done because the actual data cache file name
is constructed in a predetermined convention.  Also, an index is
associated with each date cache file.  This index is used at runtime
instead of an inode value.  Given a index, the filename is quickly
determined in the table.  This also preserves the current AFS 4.0
runtime file i/0 interface for cached data.  AFS depends heavily on
the use of the UNIX** "inode" file system primitive.  Inodes are
identifiers for fast kernel-level file access.  Inodes do not
currently exist in the OS/2 environment.  Th...