Global filesystem
Encyclopedia
A global filesystem
is one which guarantees that the same path name corresponds to the same object on all computers deploying the filesystem. That implies
Such file systems are few and not widely known but they exist.
One (and in practice the only true) example is Coda
.
A very close to global file system is Dfs
. Its namespace contains both a global part and host-dependent shortcuts.
Another similar file system is AFS
. Despite the similarity it does not qualify as a global one because the names under /afs are indirectly defined by the local host administrator.
Of course, it is still possible to use a global file system in a non-global fashion on a certain host or hosts, say by making a non-standard mount or setting up a specially crafted firewall.
It makes the globality unavailable for the isolated hosts, but only for them.
In contrast, a file system which explicitly depends on each host administrator's decisions (mounts) can never be used without strict steering, which is impossible across administrative borders. With other words, it precludes any globality.
File system
A file system is a means to organize data expected to be retained after a program terminates by providing procedures to store, retrieve and update data, as well as manage the available space on the device which contain it. A file system organizes data in an efficient manner and is tuned to the...
is one which guarantees that the same path name corresponds to the same object on all computers deploying the filesystem. That implies
- usage of a global network
- prohibition of host-dependent mountpoints
Such file systems are few and not widely known but they exist.
One (and in practice the only true) example is Coda
Coda (file system)
Coda is a distributed file system developed as a research project at Carnegie Mellon University since 1987 under the direction of Mahadev Satyanarayanan. It descended directly from an older version of AFS and offers many similar features. The InterMezzo file system was inspired by Coda...
.
A very close to global file system is Dfs
Distributed file system
Network file system may refer to:* A distributed file system, which is accessed over a computer network* Network File System , a specific brand of distributed file system...
. Its namespace contains both a global part and host-dependent shortcuts.
Another similar file system is AFS
Andrew file system
The Andrew File System is a distributed networked file system which uses a set of trusted servers to present a homogeneous, location-transparent file name space to all the client workstations. It was developed by Carnegie Mellon University as part of the Andrew Project. It is named after Andrew...
. Despite the similarity it does not qualify as a global one because the names under /afs are indirectly defined by the local host administrator.
Of course, it is still possible to use a global file system in a non-global fashion on a certain host or hosts, say by making a non-standard mount or setting up a specially crafted firewall.
It makes the globality unavailable for the isolated hosts, but only for them.
In contrast, a file system which explicitly depends on each host administrator's decisions (mounts) can never be used without strict steering, which is impossible across administrative borders. With other words, it precludes any globality.