diff -urp ./mogile_svn_r237/trunk/api/perl/MogileFS.pm ./mogile_svn_network_patch/trunk/api/perl/MogileFS.pm
--- ./mogile_svn_r237/trunk/api/perl/MogileFS.pm	2006-04-20 12:05:08.000000000 +0100
+++ ./mogile_svn_network_patch/trunk/api/perl/MogileFS.pm	2006-04-21 17:02:55.000000000 +0100
@@ -82,6 +82,8 @@ sub new_file {
             key    => $key,
             fid    => $opts->{fid} || 0, # fid should be specified, or pass 0 meaning to auto-generate one
             multi_dest => 1,
+            like_network => $opts->{like_network},
+	    dislike_network => $opts->{dislike_network},
         }) or return undef;
 
     my $dests = [];  # [ [devid,path], [devid,path], ... ]
Only in ./mogile_svn_network_patch/trunk/api/perl: version
diff -urp ./mogile_svn_r237/trunk/server/mogilefsd ./mogile_svn_network_patch/trunk/server/mogilefsd
--- ./mogile_svn_r237/trunk/server/mogilefsd	2006-04-20 12:05:08.000000000 +0100
+++ ./mogile_svn_network_patch/trunk/server/mogilefsd	2006-04-25 19:22:57.000000000 +0100
@@ -77,6 +77,7 @@ my (
     $min_free_space,
     $max_disk_age,
     $node_timeout,          # time in seconds to wait for storage node responses
+    $network_replicate,     # try and replicate copies to another network
    );
 
 # Command-line options will override
@@ -99,6 +100,7 @@ Getopt::Long::GetOptions(
     'minfreespace=i' => \$cmdline{min_free_space},
     'default_mindevcount=i' => \$cmdline{default_mindevcount},
     'node_timeout=i' => \$cmdline{node_timeout},
+    'network_replicate' => \$network_replicate,
 );
 
 $config = $DEFAULT_CONFIG if !$config && -r $DEFAULT_CONFIG;
@@ -161,6 +163,7 @@ $DEBUG          = choose_value( 'debug',
 $USE_HTTP       = ! choose_value( 'no_http', 0, 1);
 $default_mindevcount = choose_value( 'default_mindevcount', 2 );
 $node_timeout   = choose_value( 'node_timeout', 3 );
+$network_replicate = choose_value( 'network_replicate', 0);
 
 ### initial setup
 Mgd::validate_dbh();
@@ -756,6 +759,16 @@ sub replicate {
     return $retunlock->(0, "Source is no longer available replicating $fid") if $on_count == 0;
     return $retunlock->(0, "No eligible devices available replicating $fid") if @exist_devid == 0;
 
+    my %dislike_network;
+    if ($network_replicate) {
+        # try and replicate to a different network
+        foreach my $host_id (keys %on_host) {
+            my ($network) = ($Mgd::cache_host{$host_id}->{hostip} =~ m/(\d+\.\d+\.\d+\.)/);
+            $network .= '0/24';
+            $dislike_network{$network}++;
+        }
+    }
+
     my $sdevid;
 
     while ($on_count < $min) {
@@ -765,6 +778,7 @@ sub replicate {
             random => 1,
             not_on_hosts => [ keys %on_host ],
             weight_by_free => 1,
+            dislike_network => [ keys %dislike_network ],
         );
 
         # wasn't able to replicate enough?
@@ -1139,6 +1153,8 @@ use vars qw($cache_device_summary $cache
 #     weight_by_free => 1,      # find result weighted by free space
 #     max_disk_age => 5,        # minutes of age the last usage report can be before we ignore the disk
 #     not_on_hosts => [ 1, 2 ], # no devices on hosts 1 and 2
+#     like_network => [ '192.168.1.0/24'], # try and find a good device on these networks
+#     dislike_network => [ '10.0.0.0/24' ],  # try and avoid using a device on these netorks
 # );
 #
 # returns undef if no suitable device was found.  else, if you wanted an
@@ -1161,6 +1177,8 @@ sub find_deviceid {
     my $start = $opts{random} ? int(rand($devcount)) : 0;
     my %not_on_host = ( map { $_ => 1 } @{$opts{not_on_hosts} || []} );
     my $total_free = 0;
+    my @like_network = grep {$_} map { Net::Netmask->new2($_) } @{$opts{like_network} || []};
+    my @dislike_network = grep {$_} map { Net::Netmask->new2($_) } @{$opts{dislike_network} || []};
 
     # now find a device that matches what they want
     my @list;
@@ -1181,17 +1199,60 @@ sub find_deviceid {
         $total_free += $dev->{mb_free};
     }
 
+    my @liked_devices;
+    my @not_disliked_devices;
+    if (@like_network or @dislike_network) {
+        Mgd::check_host_cache();
+          
+          foreach my $dev_id (@list) {
+              my $dev = $devs->{$dev_id};
+
+              foreach my $liked_netmask (@like_network) {
+                  if ($liked_netmask->match($cache_host{$dev->{hostid}}->{hostip})) {
+                      # error("pushing $dev_id to liked_devices");
+                      push @liked_devices, $dev_id;
+                  }
+              }
+              # fixme liked devices are also not_disliked_devices
+              # so that's a waste of effort
+              foreach my $disliked_netmask (@dislike_network) {
+                  if (not $disliked_netmask->match($cache_host{$dev->{hostid}}->{hostip})) {
+                      # error("pushing $dev_id to not_disliked_devices");
+                      push @not_disliked_devices, $dev_id;
+                  }              
+              }
+          }
+
+          if (@dislike_network) {
+              if (not scalar(@not_disliked_devices)) {
+                  error("no devices left that aren't on disliked networks (need at least 3 hosts)");
+              } 
+              else {
+                  @list = @not_disliked_devices;
+              }              
+          }
+          
+          if (@like_network) {
+              if (not scalar(@liked_devices)) {
+                  error('cannot find a device on a liked network (need at least 3 hosts)');
+              } 
+              else {
+                  @list = @liked_devices;
+              }
+          }
+    }
+
     # now we have a list ordered randomly, do free space weighting
     if ($opts{weight_by_free}) {
         my $rand = int(rand($total_free));
         my $cur = 0;
-
+        
         foreach my $devid (@list) {
             $cur += $devs->{$devid}->{mb_free};
             return $devid if $cur >= $rand;
         }
     }
-
+    
     # return whole list if wanting array, else just first item
     return wantarray ? @list : shift(@list);
 }
@@ -2390,6 +2451,7 @@ sub cmd_create_open {
     my $dmid = $self->check_domain($args) or return 0;
     my $key = $args->{key} || "";
     my $multi = $args->{multi_dest} ? 1 : 0;
+    my @like_network = split(',',$args->{like_network} || '');
     my $fid = ($args->{fid} + 0) || undef; # we want it to be undef if they didn't give one
                                            # and we want to force it numeric...
 
@@ -2416,6 +2478,7 @@ sub cmd_create_open {
             random => 1,
             weight_by_free => 1,
             not_on_hosts => \@hosts,
+            like_network => \@like_network,
         );
 
         last unless defined $devid;