<vdev> ::= <diskset> | <mirror> | <raidz1> | <raidz2> | <raidz3>;
<mirror> ::= "disk" "disk" | "disk" <mirror>;
<raidz1> ::= "disk" "disk" "disk" | "disk" <raidz1>;
<vdev> ::= <diskset> | <mirror> | <raidz1> | <raidz2> | <raidz3>;
<mirror> ::= "disk" "disk" | "disk" <mirror>;
<raidz1> ::= "disk" "disk" "disk" | "disk" <raidz1>;