I didn't dig into the details of your mail too much, but a few things jumped out at me...
: - At some time in the past, a manual force merge / optimize with : maxSegments=2 was run to troubleshoot high disk i/o and remove "too many Have you tried a simple commit using expungeDeletes=true? It should be a little less intensive then a optimizing. (under the covers it does IndexWriter.forceMergeDeletes()) : - Merge policies are all at Solr 4 defaults. Index size is currently ~50M : maxDocs, ~35M numDocs, 276GB. "Solr 4 defaults" is way to vague to be meaningful: 4.0? 4.1? ... 4.4? Do you mean you are using the example configs that came with that version of Solr, or do you mean you have no mergePolicy configured and you are getting the hardcoded defaults? .. either way it's important to specify exactly which version of Solr are you running and exactly what does your entire <indexConfig/> section looks like since both the example configs and the hardcoded default behavior when configs aren't specified have evolved since 4.0-ALPHA. -Hoss
