We've seen around a 10-15% decrease in performance on average in a
virtualized environment as a first approximation, which doesn't explain
your results but might give you a place to start.
I'm pretty sure Solr isn't an issue, but my question is how much RAM is
on your underlying hardware? And how
Solr 1.4 is doing great with respect to Indexing on a dedicated physical server
(Windows Server 2008). For Indexing around 1 million full text documents
(around 4 GB size) it takes around 20 minutes with Heap Size = 512M - 1G & 4GB
RAM.
However while using Solr on a VM, with 4 GB RAM it took 50