How do I resize the dump device after a system is installed in solaris zfs?

[petulia3478]

# zfs get volsize rpool/dump
NAME        PROPERTY  VALUE       SOURCE
rpool/dump  volsize   512M        -

# zfs set volsize=1G rpool/dump

# zfs get volsize rpool/dump
NAME        PROPERTY  VALUE       SOURCE
rpool/dump  volsize   1G          -