Ubuntu Manpage: dacs.vfs - the DACS virtual filestore

Provided by: dacs_1.4.28b-3ubuntu2_amd64

NAME

       dacs.vfs - the DACS virtual filestore

DESCRIPTION

These files are part of the DACS suite.

The virtual filestore provides flexible ways for DACS and software built on top of DACS to
obtain information regardless of how or where the information is stored. The DACS core
accesses (almost) all configuration information through the virtual filestore layer,
allowing information to be more easily shared and maintained, secured, or organized for
better performance.

Sometimes it is easiest to store information in a regular file initially, where it can be
modified using an ordinary text editor, but after some growth a database might improve
performance. In some situations, accessing the information remotely, via HTTP, makes
administration more convenient or is more secure. A goal of the virtual filestore is to
make it simple to make configuration choices appropriate to a particular DACS environment,
and to change them as required. Consult dacsvfs(1)[1] for additional information.

For example, the account file used by dacspasswd(1)[2] and other components is accessed
from within DACS through the name passwds (a string called an item type). The DACS
configuration in effect determines how this is mapped to an object that contains the
account information, how an individual account name is looked up, and where the object is
located.

Each virtual filestore instance maps to either an uninterpreted sequence of bytes (e.g., a
Unix file or the output of a program) or an object that contains zero or more items, each
of which is associated with a key (i.e., the name of an item relative in its virtual
filestore context) and has an uninterpreted sequence of bytes as its value (e.g., a
database file, a Unix file containing lines having a particular keyword/value structure,
or a directory containing regular files).

The VFS[3] directive is used to specify where and how information is stored. Some commands
and functions take a VFS specification as an argument to provide a default or override a
default.

For maximum portability, a key should be composed of characters from the Portable Filename
Character Set[4]: any alphanumeric character, period, hyphen, or underscore. The true
limitation on the character set depends on the underlying storage scheme and URI syntax
constraints. There is no a priori limit on naming context or key length.

BUGS

AUTHOR

       Distributed Systems Software (www.dss.ca[8])

COPYING

       Copyright2003-2012 Distributed Systems Software. See the LICENSE[9] file that accompanies
       the distribution for licensing information.

NOTES