To answer myself, from https://docs.atlassian.com/jira/6.4.1/com/atlassian/jira/config/util/JiraHome.html#getLocalHome()
it looks like this is to do with JIRA Data Center. I was puzzled because I found it in 6.1.3 but I guess it was just early work. It doesn't appear in any searchable documentation I can find
As you have guessed, this is related to JIRA Data Center (JDC).
Under JDC, there is a "local home" used for logs, the Lucene index, configuration files, etc. and a "shared home" used for resources that all nodes need access to, such as backup directories, index snapshots, attachments, avatars, and installed plugins.
Parts of the the JDC project were already underway in JIRA 6.1, and the ability to split JIRA's home directory was one of the earliest pieces of that work.
Connect with like-minded Atlassian users at free events near you!Find a group
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no AUG chapters near you at the moment.Start an AUG