VD_OP_FLUSH
rv = vdc_do_sync_op(vdc, VD_OP_FLUSH, NULL, 0,
{VD_OP_FLUSH, DKIOCFLUSHWRITECACHE, 0,
{VD_OP_FLUSH, STRINGIZE(VD_OP_FLUSH), 0,
{X(VD_OP_FLUSH), vd_ioctl, NULL},
(1 << VD_OP_FLUSH) | \