title: Is it possible to upgrade from Solr 4.x directly to Solr 6.1?
body: <p>We are looking to upgrade from SolrCloud 4.10.3 to SolrCloud 6.1.  The documentation for Solr 6.1 is not very clear on backward compatibility.</p>
  
  <p>I came across <a href="https://support.lucidworks.com/hc/en-us/articles/203776523-How-to-upgrade-between-major-Solr-Versions" rel="noreferrer" title="post">this post</a> on the LucidWorks site.   </p>
  
  <blockquote>
    <p>The index format is backward compatible between two consecutive major
    Solr versions. So a Solr 3.x index is compatible with a Solr 4.x
    index. However if you have a Solr 1.x index and want to upgrade to
    Solr 4.x then you would need to first upgrade to Solr 3.x first.</p>
  </blockquote>
  
  <p>It was written before Solr 6.x was out, and the wording of "between two consecutive major Solr versions" is unclear.  The example skips the exact scenario that I'm interested in (skipping exactly 1 major version).</p>
  
  <p>Do I have to first upgrade to Solr 5.x and then go to Solr 6.1?</p>