basho/riak_wiki — comment on commit 08b1dab380361269c0e102fb49de36bab9e6410f
File:  line 0
By gburd:

Also, add a bit at the end.

"You might ask yourself, 'why only 50% of available RAM?' and the answer is that the other physical RAM will be used by the operating system, the Erlang VM, and by the operating system's filesystem cache (the buffer pool on Linux). That filesystem cache will translate into much faster access times (read and write) for your cluster. A second reason for the buffer is to avoid paging memory to disk. Virtual memory helps prevent failure due to out of memory but the costs of paging memory to/from disk are very high and cause noticeable impact on cluster performance."