--- /dev/null
+<facility name=block>
+ <description>block facility has events related to block read and block written.</description>
+
+ <event name=read>
+ <description>block read for disk data</description>
+ <field name="major"> <description>major number of the device</description> <int/> </field>
+ <field name="minor"> <description>minor number of the device</description> <int/> </field>
+ <field name="bytes"> <description>number of bytes read</description> <size_t/> </field>
+ </event>
+
+ <event name=write>
+ <description>Block write event </description>
+ <field name="major"> <description>major number of the device</description> <int/> </field>
+ <field name="minor"> <description>minor number of the device</description> <int/> </field>
+ <field name="bytes"> <description>number of bytes written</description> <size_t/> </field>
+ </event>
+
+
+</facility>