HAMMER is really shaping up now. Here's what works now:
     * All filesystem operations

     * All historical operations

     * All Pruning features
    Here's what is left:
     * freemap code (allocate and free big-blocks, which are 8MB blocks).

       Currently a hack so everything else can be tested, nothing is

       actually freed.
     * undo fifo and related recovery code.  Most of the API calls are

       in place, the back-end buffer reservation, flushes, and recovery

       need to be implemented.
     * big-block cleaning code (this is different from the pruning code).
     * Structural locking.  The B-Tree is fine-grained locked but the

       locks for the blockmap are just a hack (one big lock).
    These are all fairly low difficulty items, most of the infrastructure

    needed to support their function is already in place and the FIFO

    infrastructure has already been tested (just not mapped onto a blockmap

    yet).
    I have already run some tests with regards to the blockmap allocation

    model and it looks very good.   What I did was implement an array of

    blockmap entry structures rather then just an array of pointers to the

    actual physical big-blocks.  The blockmap entry structure not only has

    a pointer to the underlying physical big-block, it also has a

    bytes_free field which specifies how many bytes in the underlying

    big-block are free.
    This is the only tracking done by the blockmap.  It does not actually

    try to track WHERE in the big-block the free areas are... figuring

    that out will be up to the cleaning code.  What this gives us is the

    following:
    * Extremely fast freeing of on-disk storage elements.  The target

      physical block doesn't have to be read or written, only the governing

      blockmap entry.  With 8MB big-blocks and 32-byte blockmap entries one

      16K buffer can track 4GB worth of underlying storage, which means

      that freeing large amounts of sparse information d...
[ message continues ]

*snip*
Struggling today with a situation wherein 82 Giga-bytes of data were

moved into an IMAP trash folder on UFS2, outrunning inodes, names et al

before disk space (plenty of that left) and a cleanup that gets:
/bin/rm: Argument list too long
Unless I script it into manageable chunks....
If HAMMER fs has a better, even mechanism - even a rahter BFBI one, to

handle that sort of need for massive deletions, it will make a convert here.
Bill

Well, unless someone implements some kernel-space globbing support

(which would be nice for other reasons, alas..) then you may still be

stuck with similar issues.
of course, ls *match* | xargs -n 100 rm or something along those lines

is a perfectly good way of doing it..
Adrian
--

Adrian Chadd - adrian@freebsd.org

*snip*
Per my off-list note, have gotten much of it cleaned up with scripting

et al.
But the larger issue is indeed expanded globbing support *somewhere*.
And not just for new file systems, but old ones that have long-since

outgrown the currently available resources.
Massive drive and name space isn't a lot of use if we are short matching

utils to manage it well.
Bill

Have you decided how to implement multi-master replication yet?
--

Jason Smethers

I'm fond of telling political hotheads (which you once were, but no longer ;o)

that, before they destroy the system devised by their predecessors, they owe

it to themselves to stop and find out exactly what problems their predecessors

thought they were solving when they invented the existing system.
So -- in this instance you are both the establishment and the revolutionary at

the same time.  Could you explain in extra-bonehead language what problems you

were solving with the cluster model, and if you are still solving those problems

with the newer model?
Thanks!