The book "HBase: The definitive guide" states that
Installing different filesystems on a single server is not recommended. This can have adverse effects on performance as the kernel may have to split buffer caches to support the different filesystems. It has been reported that, for certain operating systems, this can have a devastating performance impact.
Does this really apply to Linux? I have never seen the buffer cache bigger than 300 Mbytes and most modern servers have gigabytes of RAM so splitting the buffer cache between different filesystems should not be an issue. Am I missing something else?