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dhruba borthakur commented on MAPREDUCE-2257: --------------------------------------------- A new option to distcp could trigger parallel-block copy. It cannot be used with hftp. > distcp can copy blocks in parallel > ---------------------------------- > > Key: MAPREDUCE-2257 > URL: https://issues.apache.org/jira/browse/MAPREDUCE-2257 > Project: Hadoop Map/Reduce > Issue Type: Improvement > Components: distcp > Reporter: dhruba borthakur > Assignee: dhruba borthakur > > The minimum unit of work for a distcp task is a file. We have files that are > greater than 1 TB with a block size of 1 GB. If we use distcp to copy these > files, the tasks either take a long long long time or finally fails. A better > way for distcp would be to copy all the source blocks in parallel, and then > stich the blocks back to files at the destination via the HDFS Concat API > (HDFS-222) -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.