I'm trying to compare the performance of two machines that I have. I have in both of the machines a database that was installed with the same settings. Both of the machines have the same amount of cpu(20Cores)/memory(65GB). Each machine is a vm in a dedicated esx with local disks.
I'm running the same operation in both of the machines but the results that I see in machine2 are far better then machine1 even though the hardware is the same. I was trying to find the root cause and I started from investigating the memory. I watched on the output of free -m on both of the machines and I saw that during the entire operation the buffers/shared/cached have very different values :
machine 1(avg) used - 42GB, buffers - 450MB, shared - 1.9GB, cached - 39GB
machine 2 (avg) used-58GB, buffers - 2.8GB, shared - 4GB, cached - 29GB,
From what I understood cached means that data that is recently read from disk will be saved in cache to save I/O which means that in machine1 reads should be faster because cached col is bigger(In contrary to my results).
Any idea what can explain the results ? What else can I investigate ?