[ https://issues.apache.org/jira/browse/HDFS-1940?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Bharath Mundlapudi reassigned HDFS-1940: ---------------------------------------- Assignee: Bharath Mundlapudi > Datanode can have more than one copy of same block when a failed disk is > coming back in datanode > ------------------------------------------------------------------------------------------------ > > Key: HDFS-1940 > URL: https://issues.apache.org/jira/browse/HDFS-1940 > Project: Hadoop HDFS > Issue Type: Bug > Components: data-node > Affects Versions: 0.20.204.0 > Reporter: Rajit > Assignee: Bharath Mundlapudi > > There is a situation where one datanode can have more than one copy of same > block due to a disk fails and comes back after sometime in a datanode. And > these duplicate blocks are not getting deleted even after datanode and > namenode restart. > This situation can only happen in a corner case , when due to disk failure, > the data block is replicated to other disk of the same datanode. > To simulate this scenario I copied a datablock and the associated .meta file > from one disk to another disk of same datanode, so the datanode is having 2 > copy of same replica. Now I restarted datanode and namenode. Still the extra > data block and meta file is not deleted from the datanode > [hdfs@gsbl90192 rajsaha]$ ls -l `find > /grid/{0,1,2,3}/hadoop/var/hdfs/data/current -name blk_*` > -rw-r--r-- 1 hdfs users 7814 May 13 21:05 > /grid/1/hadoop/var/hdfs/data/current/blk_1727421609840461376 > -rw-r--r-- 1 hdfs users 71 May 13 21:05 > /grid/1/hadoop/var/hdfs/data/current/blk_1727421609840461376_579992.meta > -rw-r--r-- 1 hdfs users 7814 May 13 21:14 > /grid/3/hadoop/var/hdfs/data/current/blk_1727421609840461376 > -rw-r--r-- 1 hdfs users 71 May 13 21:14 > /grid/3/hadoop/var/hdfs/data/current/blk_1727421609840461376_579992.meta -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira