kafka不能启动

近期在搭建一个kafka集群的时候。碰到一个很奇怪的问题。相关报错如下：
[2014-05-07 14:18:24,439] INFO [Kafka Server 2], Starting (kafka.server.KafkaServer)
[2014-05-07 14:18:24,457] INFO [Log Manager on Broker 2] Loading log 'kafka_metrics' (kafka.log.LogManager)
[2014-05-07 14:18:24,473] FATAL Fatal error during KafkaServerStable startup. Prepare to shutdown (kafka.server.KafkaServerStartable)
java.lang.StringIndexOutOfBoundsException: String index out of range: -1
 at java.lang.String.substring(String.java:1911)
 at kafka.log.LogManager.kafka$log$LogManager$$parseTopicPartitionName(LogManager.scala:335)
 at kafka.log.LogManager$$anonfun$loadLogs$1$$anonfun$apply$3.apply(LogManager.scala:112)
 at kafka.log.LogManager$$anonfun$loadLogs$1$$anonfun$apply$3.apply(LogManager.scala:109)
 at scala.collection.IndexedSeqOptimized$class.foreach(IndexedSeqOptimized.scala:34)
 at scala.collection.mutable.ArrayOps.foreach(ArrayOps.scala:34)
 at kafka.log.LogManager$$anonfun$loadLogs$1.apply(LogManager.scala:109)
 at kafka.log.LogManager$$anonfun$loadLogs$1.apply(LogManager.scala:101)
 at scala.collection.IndexedSeqOptimized$class.foreach(IndexedSeqOptimized.scala:34)
 at scala.collection.mutable.WrappedArray.foreach(WrappedArray.scala:32)
 at kafka.log.LogManager.loadLogs(LogManager.scala:101)
 at kafka.log.LogManager.(LogManager.scala:62)
 at kafka.server.KafkaServer.startup(KafkaServer.scala:63)
 at kafka.server.KafkaServerStartable.startup(KafkaServerStartable.scala:34)
 at kafka.Kafka$.main(Kafka.scala:46)
 at kafka.Kafka.main(Kafka.scala)
[2014-05-07 14:18:24,474] INFO [Kafka Server 2], Shutting down (kafka.server.KafkaServer)
[2014-05-07 14:18:24,476] INFO Shutdown Kafka scheduler (kafka.utils.KafkaScheduler)
[2014-05-07 14:18:24,476] INFO [Kafka Server 2], Shut down completed (kafka.server.KafkaServer)
[2014-05-07 14:18:24,477] INFO [Kafka Server 2], Shutting down (kafka.server.KafkaServer)

经过一番查找，终于知道原因,是因为在kafka的server.properties中。
log.dir=/home/data/kafka和kafka.csv.metrics.dir=/home/data/kafka
目录相同。造成的。