Looking into upgrading our solar instance from version 5 to version 8.
I worked through the index upgrading tools but it doesn’t allow upgrading an index create before version 7 into version 8.
Exception in thread "main" org.apache.lucene.index.IndexFormatTooOldException: Format version is not supported (resource BufferedChecksumIndexInput(MMapIndexInput(path="/var/solr/data/solr5_restore_test/data/snapshot.collection1.20201230023602/segments_4ya8s"))): This index was initially created with Lucene 6.x while the current version is 8.6.1 and Lucene only supports reading the current and previous major versions.. This version of Lucene only supports indexes created with release 7.0 and later.
I was wondering if there were any alternatives or if it would require reindexing everything.