title: HBase oldWALs: what it is and how can I clean it?
body: <p>We are running out of space in our small hadoop cluster so I was checking disk usage on HDFS and I saw that most of the space was occupied by the /hbase/oldWALs folder.</p>
  
  <p>I have checked in the "HBase Definitive Book" and others books, web-site and I have also search my issue on google but I didn't find a proper response...</p>
  
  <p>So I would like to know what does this folder, what is use for and also how can I free space from this folder without breaking everything...</p>
  
  <p>If it's related to a specific version... our cluster is under 5.3.0-1.cdh5.3.0.p0.30 from cloudera (hbase 0.98.6).</p>
  
  <p>Thx for your help!</p>