Home > Workload Solutions > SQL Server > White Papers > Dell EMC PowerMax Storage for Mission-Critical SQL Server Databases > Planned failover
If the node running SQL Server needs to be taken out of service, there is no need to shut down the server. The SQL Server will automatically be migrated to another node. The server will be unavailable while the persistent storage volumes are mapped to the new node. The failover time depends on the number of volumes mapped to the container and the volume un-map/map process is sequential in nature. Table 1 shows SQL server failover time and the number of persistent volumes.
Table 4. SQL server downtime and number of PVCs
Number of PVCs |
SQL server down time (Seconds) |
1 |
64 |
4 |
84 |
8 |
143 |
12 |
148 |
If the container dies and is restarted on the same node, the downtime is only 10 to 12 seconds because no volume un-map/map or volume discovery is required in this scenario.