Failover is one of the most important operations in mirroring and you need to be cautious when you failover from one server to another. There can be situations where if you failover the wrong way around, you might end up in a situation where you can potentially lose data. To perform a failover, it is important to know the Primary and Secondary SQL servers. Here is a list of validations that you can use: Ensure that Primary and Secondary SQL servers are not the same Ensure that the Primary is reachable Ensure that the Secondary is reachable Ensure that the database to be failed over exists on Primary Ensure that the database to be failed over exists on Secondary Ensure that the database to be failed over is mirrored on the Primary Ensure that the database to be failed over is in a role on the Primary “Principal” Ensure that the database to be failed over is in a role on the Secondary “Mirror” Ensure that the partner for the database to be failed is Secondary on Primary Ensure that the partner for the database to be failed is Primary on Secondary Ensure that the failover mode is not “automatic” Ensure that the database is in state “synchronized” Only if all the above conditions succeed, continue to failover the database. Please refer to the below flow chart (Flowchart 4) for a few validations that you make before you perform a failover. Flowchart 4: Validations - Failover from Primary to Secondary Validations around breaking up mirroring relationship There could be two situations where you would want to breakup mirroring: Breakup mirroring: This is the normal breakup scenario where you might want to breakup mirroring when the Primary and Secondary SQL servers are connected. Here is a list of validations that you can perform before performing a breakup. Ensure that the Primary is reachable Ensure that the database for which we need to breakup mirroring exists on the Primary Ensure that the database for which we need to breakup mirroring is mirrored
Failover is one of the most important operations in mirroring and you need to be cautious when you failover from one server to another. There can be situations where if you failover the wrong way around, you might end up in a situation where you can potentially lose data. To perform a failover, it is important to know the Primary and Secondary SQL servers. Here is a list of validations that you can use: Ensure that Primary and Secondary SQL servers are not the same Ensure that the Primary is reachable Ensure that the Secondary is reachable Ensure that the database to be failed over exists on Primary Ensure that the database to be failed over exists on Secondary Ensure that the database to be failed over is mirrored on the Primary Ensure that the database to be failed over is in a “Principal” role on the Primary Ensure that the database to be failed over is in a “Mirror” role on the Secondary Ensure that the partner for the database to be failed is Secondary on Primary Ensure that the partner for the database to be failed is Primary on Secondary Ensure that the failover mode is not “automatic” Ensure that the database is in “synchronized” state Only if all the above conditions succeed, continue to failover the database. Please refer to the below flow chart (Flowchart 4) for a few validations that you make before you perform a failover. Flowchart 4: Validations - Failover from Primary to Secondary Validations around breaking up mirroring relationship There could be two situations where you would want to breakup mirroring: Breakup mirroring: This is the normal breakup scenario where you might want to breakup mirroring when the Primary and Secondary SQL servers are connected. Here is a list of validations that you can perform before performing a breakup. Ensure that the Primary is reachable Ensure that the database for which we need to breakup mirroring exists on the Primary Ensure that the database for which we need to breakup mirroring is mirrored