The supported versions are both Solr 8.x and Solr 9.x, note that:
o Solr 8.x requires Java 8 or higher.
o Solr 9.x requires Java 11 or higher.
The minimum Solr indexing server requirements (based on physical hardware performance, not a virtual environment) are:
o Processor: 2 GHZ quad core (4 cores)
o Memory: 24 GB of RAM
o Storage: 20 GB of disk space
If you are migrating from a Lucene index to SolrCloud, you would need disk space 2 to 3 times the size of the original Lucene index. This is because MM stores much more information in the Solr index to facilitate the searching, sorting and faceting functions.