: Thanks for the reply. I'm at home right now, or I'd try this myself, but is : the suggestion that two optimize() calls in a row would resolve the issue?
it might ... I think the situations in which it happens have evolved a bit over the years as IndexWRiter has gotten smarter about knowing when it really needs to touch the disk to reduce IO. there's a relatively new explicit method (IndexWriter.deleteUnusedFiles) that can force this... https://issues.apache.org/jira/browse/LUCENE-2259 ...but it's only on trunk, and there isn't any user level hook for it in Solr yet (i opened SOLR-2532 to consider adding it) -Hoss
