A port number of 0 instructs the server to start on a free port, but this is generally discouraged because it is incompatible with setting cluster-wide firewall policies.
ECC memory is strongly recommended, as several Hadoop users have reported seeing many checksum errors when using non-ECC memory on Hadoop clusters.
配置成多个路径,FSImage和EditLog会同时写入多个路径,方便以后恢复用
不适合datanode,如果配置成RAID的话,就不需要副本了:
适合namenode:用于保护元数据信息
原文地址:http://blog.csdn.net/jiewuyou/article/details/45037353