XG Firewall Firmware Update in HA config

Question

Hello, Quick Question: 
 When new firmware are applied what is the sequence in SFOS XG? 
 When firmware is applied, is it performed in one device at a time without service loss or both with loss of service? 
 In Cyberoam HA there is loss of service 
 In Sophos UTM there is no loss of service 
 Thanks

HuberChristian · Answer

There is even in Sophos UTM's world a short outage of connectivity (maybe less than 2 Seconds). This is exactly what happens if you select Upload+Boot in XG Firewall.