By default, Virtualmin will get total and free memory from the appropriate commands for your operating system. However, if these are not accurate or do not reflect the usage you want users to see (such as in a VPS environment), this field can be set to a command that must output the following values, one per line :

1. Total real memory in bytes
2. Free real memory in bytes
3. Total swap space in bytes, or 0 if none
4. Free swap space in bytes