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Todd Lipcon commented on HDFS-2699: ----------------------------------- The idea of introducing the new format as a backward-compatible option sounds good to me. That's what we did for the CRC32C checksums - new files are written with that checksum algorithm but old files continue to operate with the old one. > Store data and checksums together in block file > ----------------------------------------------- > > Key: HDFS-2699 > URL: https://issues.apache.org/jira/browse/HDFS-2699 > Project: Hadoop HDFS > Issue Type: Improvement > Reporter: dhruba borthakur > Assignee: dhruba borthakur > > The current implementation of HDFS stores the data in one block file and the > metadata(checksum) in another block file. This means that every read from > HDFS actually consumes two disk iops, one to the datafile and one to the > checksum file. This is a major problem for scaling HBase, because HBase is > usually bottlenecked on the number of random disk iops that the > storage-hardware offers. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira