knowledge/attachments_to_filesystem/data/ir_cron.xml

<?xml version="1.0" encoding="UTF-8"?>
<openerp>
    <data noupdate="1">
        <record id="cron_move_attachments" model="ir.cron">
            <field name="name">Move attachments to filestore</field>
            <field name="active" eval="True" />
            <field name="user_id" ref="base.user_root" />
            <field name="priority" eval="-1" />
            <field name="numbercall" eval="1" />
            <field name="nextcall">2000-01-01</field>
            <field name="doall" eval="False" />
            <field name="model">ir.attachment</field>
            <field name="function">_attachments_to_filesystem_cron</field>
            <field name="args">()</field>
        </record>
    </data>
</openerp>