/usr/bin/disklayout:34
        disks = disks.filter(function (disk) {
                      ^
TypeError: Cannot call method 'filter' of undefined
    at dolayout (/usr/bin/disklayout:34:16)
    at /usr/bin/disklayout:95:3
    at zpool.listDisks (/usr/node/0.8/node_modules/zfs.js:49:12)
    at ChildProcess.exithandler (child_process.js:544:7)
    at ChildProcess.EventEmitter.emit (events.js:99:17)
    at maybeClose (child_process.js:638:16)
    at Process._handle.onexit (child_process.js:680:5)