Lost one of FTD device in HA Configuration

[vashan]

I have two Cisco Firepower 2110 in HA Configuration. I tried to perform version upgrade from 6.4. to 6.6. I got Device2 (Standbyd device) upgraded to 6.6. But the Device1 (Primary) failed the update. And the Device1 i showing up in maintenance mode after i manually rebooted Device1 after upgrade failure. I cannot access the device using SSH. I can ping the management IP. 

What is the steps i need to perform to bring back the Device1 to HA Configuration?

[nspasov]

What is the current status on the "standby" device?

• Is it now active?
• Is it up and forwarding traffic?
• Can you confirm that it is running 6.6.x?

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[vashan]

Device1 is not active - FMC registers as the device is in maintenance mode.

I dont think it is forwarding traffic since FMC registers is it in maintenance mode.

Device is is still running version 6.4

[nspasov]

What is the current status and state of device2?

[vashan]

Device2 is active and it is updated to version 6.6.

[nspasov]

Hmm. In this case, you can perhaps Break H/A > Deregister Device1 > Upgrade Device1 to 6.6.x > Register it again with the FMC > Re-create H/A