Re: How to determine if volume needs to be released

[Rick Cochran]

Thanks for the many responses.  The answer seems to be "compare the date
of the read/write copy with those of the readonly copies".

I enclose the resulting perl script in case anyone is interested.

-Rick

|Rick Cochran             607-255-7223               [EMAIL PROTECTED]|
|Cornell Materials Science Center                    [EMAIL PROTECTED]|
|E20 Clark Hall, Ithaca, N.Y. 14853          cornell!msc.cornell.edu!rick|


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#!/usr/local/bin/perl

# volume_mgr - perform daily AFS volume maintenance

# 3/9/93 rcc - initial coding


# Convert date/time format in "vos exa" commands to unix time
sub gettimes {
  local($vol) = @_;
  local(@times);
  open(zz, "vos exa $vol -localauth |") || die "unable to execute 'vos exa'\n";
  while ( <zz> ) {
    chop;
    if ( /Last Update (.*)/ ) {
      ($dow, $mnth, $day, $hr, $min, $sec, $yr) = $1 =~ 
/^(\w+)\s+(\w+)\s+(\d+)\s+(\d+):(\d+):(\d+)\s+19(\d+)$/;
      push(@times, &timelocal(($sec, $min, $hr, $day, $month{$mnth}, $yr)));
    }
  }
  @times;
}

# Determine if an AFS volume needs to be released by comparing date of
# read/write copy with dates of readonly copies.
sub changed {
  local($vol) = @_;
  local(($rwdate)) = &gettimes($vol);
  local(@rotimes) = &gettimes("$vol.readonly");
  local($rodate);
  foreach $rodate (@rotimes) {
    return 1 if $rwdate > $rodate;
  }
  return 0;
}

# Release a volume if it needs to be released.
sub release {
  local($vol) = @_;
  if ( &changed($vol) ) {
    print "Releasing volume $vol\n";
    system("vos release $vol -localauth");
  }
  else {
    print "$vol does not need to be released\n";
  }
}


# initialization
require "timelocal.pl";
%month = ( 'Jan', 0, 'Feb', 1, 'Mar', 2, 'Apr', 3, 'May', 4, 'Jun', 5,
  'Jul', 6, 'Aug', 7, 'Sep', 8, 'Oct', 9, 'Nov', 10, 'Dec', 11 );

# release some volumes
&release('rs_aix32.local.pub');
&release('rs_aix32.pub.tools');