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File system behavior

What the file system gives an application, and where it stops behaving like a local one.

POSIX compliance is the widest of the terms on this page. This term says how far a MooseFS mount matches an ordinary file system and where it does not. The other terms describe what a file has beyond its data. Extended and extra attributes are the name and value pairs that an application writes for its own purposes, and the flags that MooseFS keeps for its own. Access control lists name as many users and groups as an object needs. The permission bits name three parties. File locking is the agreement between processes to keep off a file. The Master Server holds that agreement, so the agreement applies across machines.

The last three terms are about a file over time rather than at one moment. Trash and sustained files cover a deleted file that MooseFS still keeps, either because its retention has not run out or because a client still holds the file open. A snapshot is a tree as it was at one moment. A snapshot costs no extra space until one of the two sides, the snapshot or the original tree, is written to. A quota is the limit on how much of the file system one directory subtree may take.