--- a/bin/imager.check	Wed Aug 03 10:41:51 2011 +0200
+++ b/bin/imager.check	Tue Aug 16 11:04:58 2011 +0200
@@ -95,7 +95,7 @@
 sub purge_unused {
     my ($dir, %block) = @_;
 
-    my ($total, $done);
+    my ($total, $done, $t0);
     verbose("# pass 1 - checking for unused blocks");
     verbose("#          estimating file count");
 
@@ -106,18 +106,20 @@
             opendir(my $dh => $_);
             map { $total++ if not $_ ~~ [qw<. ..>] and length > 8 } readdir $dh;
             closedir($dh);
+	    $File::Find::prune = $_ =~ /^[\d[a-f]{3}$/;	# FIXME should be configurable
         },
         "$dir/data"
     );
     verbose("#          got $total blocks/files");
 
     # progress
+    $t0 = time;
     local $SIG{ALRM} = sub {
         return alarm 1 if not $done;
-        my $speed = $done / (time - $^T + 1);
+        my $speed = $done / (time - $t0 + 1);
         verbose sprintf "# pass 1 done %5.1f%% | %25s (%*d of %d blocks)",
           100 * ($done / $total),
-          scalar(localtime($^T + $speed * ($total - $done))),
+          scalar(localtime $t0 + $total/$speed),
           length($total) => $done,
           $total;
         alarm 5;
@@ -182,16 +184,17 @@
 
     my $total = grep { $_ ne "" } keys(%block);
     my $done = 0;
+    my $t0 = time;
 
     verbose("# pass 2 - checking image completeness");
 
     # progress
     local $SIG{ALRM} = sub {
         return alarm 1 if not $done;
-        my $speed = $done / (time - $^T + 1);
+        my $speed = $done / (time - $t0 + 1);
         verbose sprintf "# pass 2 done %5.1f%% | %25s (%*d of %d blocks)",
           100 * $done / $total,
-          scalar(localtime($^T + ($total - $done) * $speed)),
+          scalar(localtime $t0 + $total/$speed),
           length($total) => $done,
           $total;
         alarm 5;