of server computers. The disks are usually organized locally using a storage
organization technique called redundant arrays of independent disks (RAID)
(described later, in Section 10.3), to give the servers a logical view of a very large
and very reliable disk. The computer and the disk subsystem continue to use the
SCSI, SAS, or Fiber Channel interface protocols to talk with each other, although
they may be separated by a network. Remote access to disks across a storage area
network means that disks can be shared by multiple computers that could run
different parts of an application in parallel. Remote access also means that disks
containing important data can be kept in a central server room where they can be
monitored and maintained by system administrators, instead of being scattered
in different parts of an organization.