[lkml]   [2007]   [Sep]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
    SubjectRe: Distributed storage. Move away from char device ioctls.
    Jeff Garzik wrote:
    > Evgeniy Polyakov wrote:
    > > Hi.
    > >
    > > I'm pleased to announce fourth release of the distributed storage
    > > subsystem, which allows to form a storage on top of remote and local
    > > nodes, which in turn can be exported to another storage as a node to
    > > form tree-like storages.
    > >
    > > This release includes new configuration interface (kernel connector over
    > > netlink socket) and number of fixes of various bugs found during move
    > > to it (in error path).
    > >
    > > Further TODO list includes:
    > > * implement optional saving of mirroring/linear information on the
    > > remote nodes (simple)
    > > * new redundancy algorithm (complex)
    > > * some thoughts about distributed filesystem tightly connected to DST
    > > (far-far planes so far)
    > >
    > > Homepage:
    > >
    > >
    > > Signed-off-by: Evgeniy Polyakov <>
    > My thoughts. But first a disclaimer: Perhaps you will recall me as
    > one of the people who really reads all your patches, and examines your
    > code and proposals closely. So, with that in mind...
    > I question the value of distributed block services (DBS), whether its
    > your version or the others out there. DBS are not very useful, because
    > it still relies on a useful filesystem sitting on top of the DBS. It
    > devolves into one of two cases: (1) multi-path much like today's SCSI,
    > with distributed filesystem arbitrarion to ensure coherency, or (2) the
    > filesystem running on top of the DBS is on a single host, and thus, a
    > single point of failure (SPOF).
    > It is quite logical to extend the concepts of RAID across the network,
    > but ultimately you are still bound by the inflexibility and simplicity
    > of the block device.
    > In contrast, a distributed filesystem offers far more scalability,
    > eliminates single points of failure, and offers more room for
    > optimization and redundancy across the cluster.
    > A distributed filesystem is also much more complex, which is why
    > distributed block devices are so appealing :)
    > With a redundant, distributed filesystem, you simply do not need any
    > complexity at all at the block device level. You don't even need RAID.
    > It is my hope that you will put your skills towards a distributed
    > filesystem :) Of the current solutions, GFS (currently in kernel)
    > scales poorly, and NFS v4.1 is amazingly bloated and overly complex.
    > I've been waiting for years for a smart person to come along and write a
    > POSIX-only distributed filesystem.

    This may provide a fast-path to reaching
    that goal.


    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to
    More majordomo info at
    Please read the FAQ at

     \ /
      Last update: 2007-09-14 22:51    [W:0.024 / U:64.748 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site