Download MooseFS 2.0.60 User`s Manual

Chapter 1
About MooseFS
MooseFS is a fault-tolerant distributed file system. It spreads data over multiple physical
locations (servers), which are visible to user as one resource. For standard file operations
MooseFS acts as any other Unix-alike filesystem:
• Hierarchical structure (directory tree)
• Stores POSIX file attributes (permissions, last access and modification times)
• Supports special files (block and character devices, pipes and sockets)
• Symbolic links (file names pointing to target files, not necessarily on MooseFS) and hard
links (different names of files that refer to the same data on MooseFS)
• Access to the file system can be limited based on IP address and/or password
Distinctive features of MooseFS are:
• High reliability (several copies of the data can be stored on separate physical machines)
• Capacity is dynamically expandable by adding new computers/disks
• Deleted files are retained for a configurable period of time (a file system level ”trash bin”)
• Coherent snapshots of files, even while the file is being written/accessed
1.1
Architecture
MooseFS consists of four components:
1. Managing servers (master servers) – Storing metadata for every file (information on
size, attributes and file location(s), including all information about non-regular files, i.e.
directories, sockets, pipes and devices).
In GPL edition only one machine, in Pro multiple number of machines for high availability
- automatic master server switch during main master failure.
2. Data servers (chunk servers) – any number of commodity servers storing files’ data and
synchronizing it among themselves (if a certain file is supposed to exist in more than one
copy).
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