File: //usr/syno/etc/readahead_custom.xml
<readahead_custom>
<custom diskModel="WD40EFRX" raidLevel="raid1">512</custom>
<custom diskModel="WD40EFRX" raidLevel="raid6">512</custom>
<custom diskModel="WD30EFRX" raidLevel="raid1">512</custom>
<custom diskModel="WD30EFRX" raidLevel="raid6">512</custom>
<custom diskModel="WD20EARX" raidLevel="raid1">512</custom>
<custom diskModel="WD20EARX" raidLevel="raid6">512</custom>
<custom diskModel="WD10EFRX" raidLevel="raid1">512</custom>
<custom diskModel="WD10EFRX" raidLevel="raid6">512</custom>
</readahead_custom>