I will be upgrading SRX3600 cluster on version 12.3X48-D85.
If I perform "request system reboot node all", would be there any impact on master while they come online after reboot? Suppose if node 1 comes online compare to node 0 then might be it gets the master role? is that right?
The snapshot need not be the same on both HD and Flash.
So I suggest keep the current snapshot on the HD as is(I believe this is from the pervious version). Create a new snapshot to save to the USB (this would be the latest one). This way you have the previous snapshot on HD and latest snapshot on flash.