Dear Friend ,
Now , we have freenas server with 12GB RAM , we added some fine tuning lines
m.kmem_size="3960M"
vm.kmem_size_max="3960M"
vfs.zfs.arc_max="1536M"
vfs.zfs.vdev.cache.size="120M" in this directory "/boot/loader.conf " ... its is correct or not , now RAM memory usage upto 5GB only and free memory space upto 7GB. In my manager to suggest , to increase RAM utilization upto 8GB using above "kmem_size_max " and "vfs.zfs.arc_max " , its possible , we need to check to increase RAM upto 8GB , please guide me its impact any performance issues again. But i dont aware about calculation of kmem_size , arc_max and vdev.cache.size" ... please help........... because only one department facing performance issues .. so my project not completed. :(