MOOSEFS(7)MOOSEFS(7)NAME
MooseFS - networking, distributed, fault-tolerant file system
DESCRIPTION
MooseFS is a networking, distributed file system. It spreads data over
several physical localisations (servers), which are visible to a user
as one resource. For standard file operations MooseFS acts as other
Unix-alike file systems. It has hierarchical structure (directory
tree), stores files' attributes (permissions, last access and modifica‐
tion times) as well as makes it possible to create special files (block
and character devices, pipes and sockets), symbolic links (file names
pointing to another files accessible locally, not necessarily on
MooseFS) and hard links (different names of files which refer to the
same data on MooseFS). Access to the file system can be limited basing
on IP address and/or password.
Distinctive features of MooseFS are:
- higher reliability (data can be stored in several copies on separate
computers)
- dynamically expanding disk space by attaching new computers/disks
- possibility of storing deleted files for a defined period of time
("trash
bin" service on a file system level)
- possibility of creating snapshot of a file, which means coherent
copy of the
whole file, even while the file is being written.
ARCHITECTURE
MooseFS installation consists of four types of machines:
- managing server (mfsmaster(8)) - single computer managing the whole
filesystem,
storing metadata for every file (information on size,
attributes and file
localisation(s), including all information about non-regular
files, i.e.
directories, sockets, pipes and devices).
- data servers (mfschunkserver(8)) - any number of commodity servers
storing files
data and replicating it among themselves (if a certain file
is supposed to
exist in more than one copy).
- metadata backup servers (mfsmetalogger(8)) - any number of servers,
all of
which store metadata changelogs and periodically downloading
base metadata file;
it's easy to run mfsmaster(8) process on such machine when
primary master
stops working.
- client computers referring to MooseFS stored files - any number of
machines with
working mfsmount(8) process that communicates with the manag‐
ing server to
receive and modify file information and with chunkservers to
exchange actual
file data.
Metadata is stored in memory of the managing server and simultaneously
is being saved on disk (as a periodically updated binary file and imme‐
diately updated incremental logs). The main binary file as well as the
logs are replicated to metaloggers (if present).
File data is divided to fragments (chunks) of maximum size 64MB each
which are stored as files on selected disks on data servers
(chunkservers). Each chunk is saved on different computers in a number
of copies equal to a "goal" for the given file.
REPORTING BUGS
Report bugs to <bugs@moosefs.com>.
COPYRIGHT
Copyright 2008-2009 Gemius SA.
MooseFS is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation, version 3.
MooseFS is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License along
with MooseFS. If not, see <http://www.gnu.org/licenses/>.
SEE ALSOmfschunkserver(8), mfsmaster(8), mfstools(1), mfsmount(8)MooseFS 1.6.9 November 2009 MOOSEFS(7)
