See What is a Solr collection/core/shard/replica? for help in distinguishing these critical Solr concepts.
Standard backups in the SearchStax Managed Search service rely on the principle that every Solr node contains a replica of every collection. Therefore, it is sufficient to back up one node while the remaining nodes continue to serve queries.
A sharded collection splits the index across multiple nodes. Backing up one node does not capture the full index.
For this reason, if Managed Search detects sharding, it will refuse to proceed with the backup.
Some of our Platinum and Platinum Plus clients require sharded collections. For them, we can implement custom backup solutions through a Service Request. Please contact SearchStax Support to explore this option.
Questions?
Do not hesitate to contact the SearchStax Support Desk.