to as the time in flight. Storage Components All storage systems are made up of servers with specialized programs to manage and monitor the memory in disk drives and flash memory. The programs www.TechnicalPDF.com on servers also handle access to storage. Newer storage systems are composed of standard off-the-shelf computers. Storage systems additionally require fiber- optic cabling links between the storage area network and LANs and broadband networks. Traffic on the links may be routed via specialized protocols. Memory-Flash vs. Spinning Memory in storage systems is complex and can be architected, or put together, a number of different ways. The data stored is held either in spinning disks or flash memory. Some storage systems use a combination of both spinning disks and flash memory. Spinning disk memory is held in drives made up of metal platters with magnetic coating on which data files are stored. See Figure 2-5 below to see a spinning disk for data storage. A read-write arm attachment accesses data on the hard drive while it is spinning. www.TechnicalPDF.com A read-write arm to access and add data Spinning disc containing data Figure 2-5 A spinning disk for data storage. (Photo by olegdudko/123RF) www.TechnicalPDF.com Another option in addition to spinning discs is to use flash memory. Flash memory consists of interconnected flash memory chips in which data is stored. Flash memory has the advantages of being faster to access and requiring less electricity. However, after a finite amount of times that data is "written" onto flash memory, it will physically wear out. Some storage systems contain both types of memory and others consist of all flash memory. Kaminario, EMC's DSSD, and Quorum are examples of companies that offer storage systems made entirely of flash memory. Infinidat offers a hybrid system with flash memory for the most frequently accessed data and spinning discs for the rest of the data. NetApp sells both hybrid and all-flash storage. There is disagreement in the industry over which approach, 