<h1>Backup space and automatic deletion</h1>
<h2>Backup space</h2>
<figure>
  <img src="/images/wonderpen/guides/backup_03.en.png" width="320" alt=""/>
  <figcaption>Limit maximum size of backups</figcaption>
</figure>
<p>To prevent the backup folder from being too large, you can set the maximum space for backup files. If the backup exceeds this space, WonderPen will <strong>automatically delet</strong>e the oldest backup.</p>
<h2>Smart deleting</h2>
<p>Most of the time, the more recent the backups, the more useful they are, and the shorter the time interval, the better. For example, you may want to have access to backups for each hour of the last 24 hours, but for backups from a few weeks ago you can be more cursory and one backup record per day will suffice.</p>
<p>By default, WonderPen will delete the oldest backups in order, but you can also turn on <strong>Smart Deleting</strong> to let WonderPen delete backups in a smarter way.</p>
<figure>
  <img src="/images/wonderpen/guides/backup_05.en.png" width="712" alt=""/>
  <figcaption></figcaption>
</figure>
<p>The default rules for smart deleting backups are as follows:</p>
<ul>
<li>The last 10 backups are always kept (unless the backup space limit is exceeded)</li>
<li>For backups in last 24 hours, only keep one per hour</li>
<li>For backups older than 24 hours, only keep one per day</li>
<li><strong>[Optional]</strong> For backups older than 30 days, only keep one per week</li>
<li><strong>[Optional]</strong> For backups older than 90 days, only keep one per month</li>
<li>If the backup space exceeds the limit, the oldest backup will be deleted</li>
</ul>
<p>The 4th and 5th rules are optional, and they are selected by default. If they are not selected, only the first 3 rules and the last rule will be executed.</p>
