Server refuses to use swap partition
You're reading this wrong, and barely using your memory.
MemTotal: 66000044 kB = 63GB available to the system
MemFree: 11824808 kB = 11GB with nothing at all used.
Buffers: 1498068 kB = 1.4GB
Cached: 48842440 kB = 46GB of data from the drive that is kept in otherwise unoccupied memory
SwapCached: 0 kB
Active: 5350660 kB = 5.1GB of memory that is actually used by applications.
When you read data from disk, it goes into memory. If nothing else is competing for the memory, that file is left in memory until an application tries to use the space. Whenever a file is read from disk, the cache is checked first.
You're barely using your memory for applications, and even with the cache you've got a lot of leftover memory to work with. You server shouldn't be utilizing swap space with that light of a memory load.