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http://wiki.apache.org/hadoop/Hbase/HowToMigrate

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  This job takes an empty input and output directory.  It will first run 
through your filesystem to find all mapfiles to convert, write a file to the 
input directory listing all files, and then startup the mapreduce job to do the 
convertions.
  
+ Here is how to you'd run a job that had /tmp/input and /tmp/output as input 
and output directories and that specified a split size of about 1k per map:
+ 
+ {{{$./bin/hadoop jar ../trunk/build/hbase-0.20.0-dev.jar hsf2sf 
-Dmapred.max.split.size=1024 /tmp/input /tmp/output}}}
+ 
+ If you don't set mapred.max.split.size down from default, you'll likely end 
up with one map only doing all rewrites.
+ 
  Now, run the hbase migration script.  If you have run the mapreduce job, it 
will notice that all storefiles have been rewritten and will skip the rewrite 
step.  Otherwise, the migration script first does this convertion.
+ 
+ BEFORE you start, set the following hbase-site.xml parameter, 
{{{hbase.hregion.memstore.block.multiplier}}}, to 100 (Don't forget to set it 
back down when the migration finishes).
+ 
+ Run the migrate as follows:
  
  {{{$./bin/hbase migrate upgrade}}}
  

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