computeMeta
Computes HDFS metadata from block files. If a block file is specified, it will compute the checksums from the block file, and save it to the specified output metadata file.
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CAUTION
Use this command with caution. If the block file is corrupt and you overwrite its meta file, it will show up as "good" in HDFS, but you can’t read the data. Only use as a last measure, and when you are 100% certain the block file is not corrupted. |
The usage is as follows:
$ hdfs debug computeMeta -block <block-file> -out <output-metadata-file>-block block-file |
An absolute path for the block file on the local file system of the data node |
-out output-metadata-file |
An absolute path for the output metadata file to store the checksum computation result from the block file |