private void printUsage() {
    System.out.println("usage: hbase " + TOOL_NAME + " command ...");
    System.out.println("Available commands:");
    System.out.printf(" %-15s Validate co-processors are compatible with HBase%n",
      VALIDATE_CP_NAME);
    System.out.printf(" %-15s Validate DataBlockEncodings are compatible with HBase%n",
      VALIDATE_DBE_NAME);
    System.out.printf(" %-15s Validate HFile contents are readable%n", VALIDATE_HFILE);
    System.out.println("For further information, please use command -h");
  }
Tool for validating that cluster can be upgraded from HBase 1.x to 2.0
<p>
Available validations:
<ul>
<li>validate-cp: Validates Co-processors compatibility</li>
<li>validate-dbe: Check Data Block Encoding for column families</li>
<li>validate-hfile: Check for corrupted HFiles</li>
</ul>
</p>
hbase-server/src/main/java/org/apache/hadoop/hbase/tool/PreUpgradeValidator.java