Tuning the operating system
In Hadoop, we mostly use Linux-based operating systems, so the settings we talk about will be restricted to any Linux-based systems.
The first important thing to consider is making sure that the hardware is optimal with latest drivers for motherboard components and the right kind of memory modules with matching bus speed. The BIOS settings are tuned to be optimal like disable power saving mode, VT flag enabled, 64-bit architecture, the right cabling for disk enclosures (Just a bunk of disks (JBOD)). Multiple CPUs with at least a quad core per CPU socket and high bandwidth bonded interface cards. Racks with support for 1U or 2U servers, with rack top switches which can support network traffic from a large Hadoop cluster.
The hardware configuration will vary according to the Hadoop components like whether it is a Namenode, Datanode, HBase master, or region server. Also, whether the work load is I/O intensive or CPU intensive. There will always be a race between right...