BigMemory 4.4.0 | Upgrade and Migration Guide | Installing Maintenance Version Upgrades for 4.2 | Preparing for Maintenance Version Upgrades for 4.2
 
Preparing for Maintenance Version Upgrades for 4.2
Before attempting to perform a rolling upgrade for 4.2, confirm the following:
*Ensure that all of the Terracotta servers and clients in the target cluster are running the same version of Terracotta.
*Ensure that the upgrade is intended for the version of Terracotta being run in your cluster.
*If persistence is enabled in your cluster, we recommend that you back up your data folder before upgrading, as described in "Database Backup Utility (backup-data) in the BigMemory Max Administrator Guide.
Note:
A non-persistent cluster without mirror servers cannot be upgraded without losing all the data.