Update methodology page after OS upgrade of load drivers (elastic#177)

Relates elastic#175

Author: dliappis

external/pages/index.html

@@ -337,24 +337,36 @@ <h4>Current environment</h4>
         <li>CPU: <a href="https://ark.intel.com/de/products/97128/Intel-Core-i7-7700-Processor-8M-Cache-up-to-4_20-GHz">Intel(R) Core(TM) i7-7700 CPU @ 3.60GHz</a></li>
         <li>RAM: 32 GB</li>
         <li>SSD: <a style="font-family:monospace;" href="https://www.micron.com/~/media/documents/products/data-sheet/ssd/1100_ssd.pdf">Micron_1100_MTFDDAK512TBN</a></li>
-        <li>OS: Linux kernel version 4.13.0-45</li>
+        <li>OS for Rally load driver servers:
+          <ul>
+            <li>Linux kernel version 4.15.0-76</li>
+          </ul>
         </li>
-        <li>OS TUNING:
-            <ul>
-                <li style="font-family:monospace;">/sys/kernel/mm/transparent_hugepage/enabled = always</li>
-                <li style="font-family:monospace;">/sys/kernel/mm/transparent_hugepage/defrag = always</li>
-            </ul>
+        <li>OS for Elasticsearch target servers:
+          <ul>
+            <li>Linux kernel version 4.13.0-45</li>
+            <li style="font-family:monospace;">/sys/kernel/mm/transparent_hugepage/enabled = always</li>
+            <li style="font-family:monospace;">/sys/kernel/mm/transparent_hugepage/defrag = always</li>
+          </ul>
         </li>
         <li>JVM: OpenJDK 11.0.2</li>
       </ul>
       <p>All machines are connected via a dedicated 10 GBit switched network.</p>
       <h4>History of changes</h4>
       <ul>
-        <li>2019-12-12</li>
+        <li>2020-02-07:</li>
+        <ul>
+          <li>Performed OS package upgrade for load driver server used for tracks `nested`, `noaa`, `pmc`, `http_logs` and switched to kernel `4.15.0-76-generic`.</li>
+        </ul>
+        <li>2020-02-04:</li>
+        <ul>
+          <li>Performed OS package upgrade for load driver server used for tracks `geonames`, `geopoint`, `percolator`, `nyc_taxis` and switched to kernel `4.15.0-76-generic`.</li>
+        </ul>
+        <li>2019-12-12:</li>
         <ul>
           <li>Replaced data disk on first target machine used by the tracks `nested`, `noaa`, `pmc`, `http_logs` with another identical model (Micron_1100_MTFDDAK512TBN).</li>
         </ul>
-        <li>2019-04-25</li>
+        <li>2019-04-25:</li>
         <ul>
           <li>Switch to new benchmarking hardware and add benchmarks for default distribution</li>
         </ul>