Migration

Migration moves a VM running Pervasive PSQL from one physical host to another. The memory, storage, and network connectivity of the VM are typically migrated to the destination. Depending on the hypervisor, migration is sometimes referred to as “live” migration or “hot” migration.

With a “live” or “hot” migration, client connections to Pervasive PSQL remain intact. This allows changes to hardware or resource balancing. With a “cold” migration, network connectivity is interrupted because the VM must boot. Client connections to Pervasive PSQL must be reestablished.

A migration environment has only one instance of Pervasive PSQL running, which makes the environment somewhat vulnerable if the host machines crashes or must be quickly taken offline. Also, if the shared storage fails, the database engine cannot process reads from or writes to physical storage. Some hypervisors offer a migration solution that does not use shared storage.

Pervasive PSQL Vx Server is the preferred product for migration environments. As long as virtual MAC addresses and host names remain the same after the VM migrates, PSQL Vx Server continues to operate normally. The product key remains in the “active” state.

You can use Pervasive PSQL Server, but the product key changes to “failed validation” state when a migration occurs to another host. The database engine runs for a limited time (the failed-validation period) with a key in failed validation. Provided that you migrate back to the original host before the failed-validation period expires, the database engine operates normally.

No special steps are required to install or configure Pervasive PSQL in a migration environment. Refer to the hypervisor documentation.