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