I have the next topology Master <----> Distribution Master (EC2 Instance) <---> SlaveServer Distribution Master is slave of Master and Master of SlaveServer. Master and Slave are in different cities and the replication needs to be Asynchronous. The EC2 instance just get data from Master and replicate to the Slave when gets connection. Do you think i need SSD volumes for the Replication Master? Or a cold HDD (sc1) will be enough?. With a cold HDD i can get more space for much lower price. Thanks in advance.