Secondary-Storage Management 二级存储管理 Since main memory(primary storage)is volatile and too small to accommodate all data and programs permanently, the computer system must provide secondary storage to back up main memory. 由于主存(基本存储器)是易失性的,而且太小不足以永久保存所有的数据和程 序,计算机系统必须提供二级存储器备份主存 Most modern computer systems use disks as the principle on-line storage medium, for both programs and data 多数现代计算机系统采用磁盘作为程序和数据的基本联机存储介质 The operating system is responsible for the following activities in connection with disk management 在同磁盘管理有关的活动中,操作系统负责下列事务 Free space management空闲空间管理 Storage allocation存储器分配 Disk scheduling磁盘调度 Applied Operating System Concepts 3.5Applied Operating System Concepts 3.5 Secondary-Storage Management 二级存储管理 • Since main memory (primary storage) is volatile and too small to accommodate all data and programs permanently, the computer system must provide secondary storage to back up main memory. 由于主存（基本存储器）是易失性的，而且太小不足以永久保存所有的数据和程 序，计算机系统必须提供二级存储器备份主存 • Most modern computer systems use disks as the principle on-line storage medium, for both programs and data. 多数现代计算机系统采用磁盘作为程序和数据的基本联机存储介质 • The operating system is responsible for the following activities in connection with disk management: 在同磁盘管理有关的活动中，操作系统负责下列事务： – Free space management 空闲空间管理 – Storage allocation 存储器分配 – Disk scheduling 磁盘调度