POSIX compliance

The following features from POSIX are not supported by Parallelstore:

• Hard links are not supported.
• mmap support with MAP_SHARED will be consistent from a single client only.
• Char devices, block devices, and sockets and pipes are not supported.
• User and group quotas are not supported.
• setuid(), setgid() programs, supplementary groups, and POSIX ACLs are not supported within the DFS namespace.
• Access time, change time, and modify time might not be updated correctly.
• Flock is not supported.
• Block size in stat buf is not accurate, as it does not account for holes or extended attributes.
• Some parameters reported with statfs, such as the number of blocks, files, or free and available space, are not supported.
• POSIX permissions inside an encapsulated namespace are not supported.
• DFS directories don't include the . (current directory) and .. (parent directory) directory entries that are known from other POSIX file systems. Commands like ls -al won't include these entries in their output. Those directory entries are not required by POSIX, so this is not a limitation to POSIX compliance. But scripts that parse directory listings under the assumption that those dot directories are present may need to be adapted to to correctly handle this situation. Note that operations like cd . or cd .. will still succeed in dfuse-mounted POSIX containers.