Respuesta :
1. linux is a relatively light-wt OS so it doesnt require lots of memory. but it is for web service so its work load may vary greatly due to demands. its better to have more memory. add 2GB for a total of 4GB
2. windows is a heavy OS n requires loads of memory. to run a windows server, it needs at least 8GB n may be up to 16GB to be on the safe side
3. storage server does not require much memory either. if u want to lower utilization from 85% to 60%, add 2GB for a total of 4GB
The minimum memory requirement for a linux server running apache is 1GB while a Windows server is 2GB (which is a joke.)
Realistically I recommend 4GB for the linux server to handle the occasional spikes for web services and 8GB to 16GB for the Windows server.
The memory requirement for a storage server is not very high. To keep the utilization below 60%, it can be upgraded to 4GB which should be plenty.