From my understanding, With DAC mode activated, it makes it easier for complete datacenter switchovers to activate passive databases at another data center. With that mode set. My question is if a partial switchover can take place where some of the active databases remain active on primary data center and some of the other databases become active at the other data center?  And manually control that behavior?  For example, 8 servers at primary, with 2 copies of each database(active and passive), and a secondary site with 2 more copies on 8 servers, with one being lagged and the other passive.   And lets say 2 servers go down at primary so that both copies(active and passive) are not available, can we fire up and make active 2 servers at secondary site to now become active database copy holder?

Thanks,

Neil

Yes, but that would not involve DAC mode. DAC mode is intended when  a manual datacenter switchover is required. i.e. the primary datacenter is down and is not something done lightly. Its an all or nothing thing

If you want to activate databases in the secondary DC, then remove any activation blocks and you can do that. No DAC mode commands required. 

Thanks,

To be clear about this, I want the DAC mode enabled so it can be an ALL or nothing option;however, if enabled, at the same time, do I still have the ability to manually fire up Active database copies at secondary site in the event of a mini disaster, where only part of primary data center is down?   I cannot find any documentation about this, only complete site failover with DAC mode set.

Neil

Thanks,

To be clear about this, I want the DAC mode enabled so it can be an ALL or nothing option;however, if enabled, at the same time, do I still have the ability to manually fire up Active database copies at secondary site in the event of a mini disaster, where only part of primary data center is down?   I cannot find any documentation about this, only complete site failover with DAC mode set.

Neil

Yes. Absolutely. As I mentioned above, remove any activation blocks you may have in place on the servers or database copies in the secondary site and activate the databases there as you would normally. DAC mode has no relationship to that.

As long as you can maintain quorum, the databases can be activated.