diff --git a/checkin_notes b/checkin_notes
index 45ff8d1d85..2a7d2dac62 100644
--- a/checkin_notes
+++ b/checkin_notes
@@ -749,3 +749,10 @@ Charlie 19 Jan 2012
     clientgui/
         mac/
             SetupSecurity.cpp
+
+David  19 Jan 2012
+    - storage simulator work
+
+    ssim/
+        ssim.cpp
+        ssim.php
diff --git a/ssim/ssim.cpp b/ssim/ssim.cpp
index 340de05303..6b226029f8 100644
--- a/ssim/ssim.cpp
+++ b/ssim/ssim.cpp
@@ -24,6 +24,7 @@
 //  [--host_life_mean x]
 //  [--connect_interval x]
 //  [--mean_xfer_rate x]
+//  [--file_size x]
 //
 // outputs:
 //   stdout: log info
@@ -76,6 +77,8 @@ struct PARAMS {
     double host_life_mean;
     double connect_interval;
     double mean_xfer_rate;
+    double file_size;
+    double sim_duration;
 
     int replication;
     int coding_levels;
@@ -87,6 +90,8 @@ struct PARAMS {
         host_life_mean = 100.*86400;
         connect_interval = 86400.;
         mean_xfer_rate = .2e6;
+        file_size = 1e12;
+        sim_duration = 1000.*86400;
         coding_levels = 1;
         codings[0].n = 10;
         codings[0].k = 6;
@@ -96,11 +101,13 @@ struct PARAMS {
     }
     int parse_policy(const char* filename) {
         int n;
+        char buf[256];
         FILE* f = fopen(filename, "r");
         if (!f) {
             fprintf(stderr, "No policy file %s\n", filename);
             exit(1);
         }
+        fgets(buf, sizeof(buf), f);     // title
         n = fscanf(f, "%d", &replication);
         if (n != 1) {
             fprintf(stderr, "parse error in %s\n", filename);
@@ -976,6 +983,8 @@ int main(int argc, char** argv) {
             p.connect_interval = atof(argv[++i]);
         } else if (!strcmp(argv[i], "--mean_xfer_rate")) {
             p.mean_xfer_rate = atof(argv[++i]);
+        } else if (!strcmp(argv[i], "--file_size")) {
+            p.file_size = atof(argv[++i]);
         } else {
             fprintf(stderr, "bad arg %s\n", argv[i]);
             exit(1);
@@ -992,10 +1001,10 @@ int main(int argc, char** argv) {
         sim.insert(new HOST);
     }
 #endif
-    DFILE* dfile = new DFILE(1e12);
+    DFILE* dfile = new DFILE(p.file_size);
     sim.insert(dfile);
 
-    sim.simulate(1000*86400);
+    sim.simulate(p.sim_duration);
 
     printf("%s: simulation finished\n", now_str());
     dfile->print_stats();
diff --git a/ssim/ssim.php b/ssim/ssim.php
index 2dd9139901..cc45e8749f 100644
--- a/ssim/ssim.php
+++ b/ssim/ssim.php
@@ -16,18 +16,24 @@ function parse_input_file($filename) {
     $x = null;
     $x->name = $filename;
     $x->policy = array();
+    $x->policy_name = array();
     $f = fopen($filename, "r");
     if (!$f) die("no file $filename\n");
     while (($buf = fgets($f)) !== false) {
         $w = explode(" ", $buf);
         switch ($w[0]) {
         case "policy":
-            $x->policy[] = trim($w[1]);
+            $pfile = trim($w[1]);
+            $x->policy[] = $pfile;
+            $g = fopen($pfile, "r");
+            $name = fgets($g);
+            fclose($g);
+            $x->policy_name[] = trim($name);
             break;
         case "host_life_mean":
             $x->host_life_mean = array();
             for ($i=1; $i<count($w); $i++) {
-                $x->host_life_mean[] = (double)($w[$i]);
+                $x->host_life_mean[] = 86400 * (double)($w[$i]);
             }
             break;
         case "connect_interval":
@@ -36,6 +42,9 @@ function parse_input_file($filename) {
         case "mean_xfer_rate":
             $x->mean_xfer_rate = (double)($w[1]);
             break;
+        case "file_size":
+            $x->file_size = (double)($w[1]);
+            break;
         }
     }
     fclose($f);
@@ -46,19 +55,20 @@ function make_graph($input, $prefix, $title, $index) {
     $gp_filename = $input->name."_$prefix.gp";
     $f = fopen($gp_filename, "w");
     fprintf($f, "set terminal png small size 1024, 768
-set title \"$title\"
 set yrange[0:]
-");
+set ylabel \"$title\"
+set xlabel \"Mean host lifetime (days)\"
+plot ");
     $n = sizeof($input->policy);
-    $i = 0;
-    foreach ($input->policy as $p) {
+    for ($i=0; $i<$n; $i++) {
+        $p = $input->policy[$i];
+        $pname = $input->policy_name[$i];
         $fname = $input->name."_$p.dat";
-        fprintf($f, "plot \"$fname\" using 1:$index title \"$p\" with lines");
+        fprintf($f, "\"$fname\" using 1:$index title \"$pname\" with lines");
         if ($i < $n-1) {
             fprintf($f, ", \\");
         }
         fprintf($f, "\n");
-        $i++;
     }
     fclose($f);
     $png_filename = $input->name."_$prefix.png";
@@ -89,18 +99,20 @@ foreach ($input->policy as $p) {
         die("no policy file '$p'\n");
     }
     foreach ($input->host_life_mean as $hlm) {
-        $cmd = "ssim --policy $p --host_life_mean $hlm --connect_interval $input->connect_interval --mean_xfer_rate $input->mean_xfer_rate > /dev/null";
+        $cmd = "ssim --policy $p --host_life_mean $hlm --connect_interval $input->connect_interval --mean_xfer_rate $input->mean_xfer_rate --file_size $input->file_size > /dev/null";
         echo "$cmd\n";
         system($cmd);
-        list($du, $ul, $dl, $ft) = parse_output_file("summary.txt");
-        fprintf($datafile, "$hlm $du $ul $dl $ft\n");
+        list($ft, $du, $ub, $db) = parse_output_file("summary.txt");
+        $hlmd = $hlm/86400;
+        $du_rel = $du/$input->file_size;
+        fprintf($datafile, "$hlmd $ft $du_rel $ub $db\n");
     }
     fclose($datafile);
 }
 
-make_graph($input, "du", "Disk usage", 2);
-make_graph($input, "ub", "Upload bandwidth", 3);
-make_graph($input, "db", "Download bandwidth", 4);
-make_graph($input, "ft", "Fault tolerance", 5);
+make_graph($input, "ft", "Fault tolerance", 2);
+make_graph($input, "du", "Relative disk usage", 3);
+make_graph($input, "ub", "Upload bandwidth (Mbps)", 4);
+make_graph($input, "db", "Download bandwidth (Mbps)", 5);
 
 ?>