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Annotation of wikisrc/projects/project/new-automounter.mdwn, revision 1.6

1.1       dholland    1: [[!template id=project
                      2: 
1.2       dholland    3: title="New automounter"
1.1       dholland    4: 
                      5: contact="""
1.4       dholland    6: [tech-kern](mailto:tech-kern@NetBSD.org)
1.1       dholland    7: """
                      8: 
                      9: mentors="""
                     10: """
                     11: 
                     12: category="filesystems"
                     13: difficulty="medium"
                     14: duration="3 months"
1.6     ! maya       15: done_by="Tomohiro Kusumi (for DragonflyBSD)"
1.1       dholland   16: 
                     17: description="""
                     18: NetBSD currently uses amd for automatically mounting (network) file systems. This software package implements an automounter file system as a userland NFS daemon. While this generally works it has major drawbacks:
                     19: 
                     20: * File systems are not mounted directly on the desired mount point. As a result applications frequently use incorrect pathnames (e.g. `/amd/server/home/user` instead of `/home/user`) for automatically mounted directories or files beneath them. This is especially problematic in heterogeneous enviroments where not all machines use the same automounter.
                     21: * The automounter daemon cannot handle high I/O load very well; file access occasionally fails with intermittent errors.
1.2       dholland   22: * Userland NFS daemons are prone to deadlocking.
1.1       dholland   23: 
                     24: The milestones of this project are:
                     25: 
                     26: * implement a new automounter solution which has configurable mount points
1.2       dholland   27: * improve behavior under load I/O
1.1       dholland   28: * show benchmarks and implement automated tests
                     29: 
1.2       dholland   30: There are at least two possible approaches: one is to port FreeBSD's
                     31: autofs(4), which is an in-kernel file system. This has the advantage
                     32: of already existing, and being at least loosely Linux and Solaris
                     33: compatible. (One could also write a new autofs but that doesn't seem
                     34: like a dominant strategy.)
                     35: 
                     36: Another possible approach is a new userland daemon using puffs.
1.3       dholland   37: 
                     38: Note that automount configuration is a complex and largely unsolved
                     39: problem. While it's desirable to be compatible with existing
                     40: automounter configuration (because often organizations like to
                     41: distribute automounter maps through NIS or other facilities) it's also
                     42: desirable to have a simple, comprehensible, and cogent configuration
                     43: scheme and these desires are rather at odds.
1.1       dholland   44: """
                     45: ]]