4010-initial-incremental.html

   1 <meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
   2 <link rel="stylesheet" href="style.css" type="text/css"/>
   3 <script src="code.js" type="text/javascript"></script>
   4
   5 <h1>Initial qemu push-mode incremental backup</h1>
   6
   7 <ul>
   8   <li>drive-backup introduced in 2015</li>
   9   <li>create a new bitmap with a full backup</li>
  10   <li>future incremental backups use the prior state of the bitmap to
  11     create external file, as well as reset the bitmap</li>
  12 </ul>
  13
  14 <p>Full backup
  15   <table>
  16     <tr>
  17       <td style="font-size:20px;">Image.qcow2</td>
  18       <td style="font-size:20px;">BackupFull.qcow2</td>
  19     </tr>
  20     <tr>
  21       <td>
  22         <table class="disk">
  23           <tr>
  24             <th>A</th><th>-</th><th>A</th><th>A</th>
  25             <th>-</th><th>A</th><th>-</th><th>-</th>
  26           </tr>
  27           <tr>
  28             <td>-</td><td>-</td><td>-</td><td>-</td>
  29             <td>-</td><td>-</td><td>-</td><td>-</td>
  30           </tr>
  31         </table>
  32       </td>
  33       <td>
  34         <table class="disk">
  35           <tr>
  36             <th>A</th><th>-</th><th>A</th><th>A</th>
  37             <th>-</th><th>A</th><th>-</th><th>-</th>
  38           </tr>
  39         </table>
  40       </td>
  41     </tr>
  42   </table>
  43 </p>
  44
  45 <p class="attribution">See also this 2015 KVM Forum presentation:
  46   <a href="https://www.youtube.com/watch?v=a2BNswm_yf8">Incremental
  47     backups: Good things come in in small packages!</a>, John Snow</p>