Once a file is locked over NFS, it turns off all local memory caching on the file (which means every thing that is done to the file now happens over the remote NFS link -- read slow) until _all_ processes that had the file open close (even after the lock has been released). You may be seeing an 18 second delay because the file is large and NFS is using network mode instead of local cache mode to open and read the data. How big is the file and how long does it take to copy the entire file to the server the B process is running on? This is one of the major issues with NFS that vendors like NetAPP would have you ignore.


-Waswas

In reply to Re: Pack and off_t for fcntl()? by waswas-fng
in thread Pack and off_t for fcntl()? by Anonymous Monk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.