Re: Filesystem monitoring question

From: Cornelis Swanepoel (rools.ster_at_gmail.com)
Date: 11/18/05

  • Next message: Eric Anderson: "Re: Filesystem monitoring question" 
    Date: Fri, 18 Nov 2005 15:29:30 +0000
To: Daniel Ellard <ellard@eecs.harvard.edu>

    Before all else let me just say that my programming experience is confined
    to userland but I am very eager to learn about interaction with the FreeBSD
    kernel.

    There are many possible answers to this question. Can you explain
    > more about exactly what you need?

    This will be a server setup from scratch to accomodate the requirements.
    Currently the share is a full partition but it can be setup on the new
    server as a directory.
    A number of SMB and NFS clients, around 30, will need to write to this
    directory.
    Writing to the directory is 24/7 since some clients VPN into the network
    from different time zones.

    When they have completed a write operation I need to trigger some code that
    will act upon the file just written.
    This code generates a unique id for the file, stats the file, compresses the
    file(if over set limit), generates a preview of the file and stores some
    info about the file and its owner in a MySQL db and a log on a seperate
    machine.
    It then moves the file to a different location on the same machine (which is
    inaccesible to the NFS and SMB clients) and renames it as its unique
    identifier.

    At this point it is out of my hands.

    Depending on what you can and cannot access ... If everything .. goes
    > through VFS, that would work. But if
    >
    it's a production server, you might not be able to get permission to
    > fiddle with the kernel.

    This machine will be built from scratch and any kernel fiddling is possible.

    ktrace might do everything you need, but I understand that it has an
    > impact on system performance under load. I don't know if that matters
    > to you at all. It also might be awkward if the SMB and NFS servers
    > are kernel processes. (I just don't know; I've only used ktrace on
    > ordinary user-land processes, and not even much of that.)

    >From the limited research I've done it seems that ktrace might not be the
    answer and I've been looking more into kqueue.
    I will definitely look into the VFS option.

    As I said at the start, this is all new to me and I greatly appreciate the
    feedback so far.

    If my explaination of the requirements is lacking please let me know
    specifically and I can elaborate.

    Thanks again and any further suggestions would be much appreciated.

    Cornelis
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  • Next message: Eric Anderson: "Re: Filesystem monitoring question"

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