Storage Hierarchy 存储层次 ° Storage systems organized in hierarchy存储系统分层组织 Speed速度 cost成本 volatility易失性 Caching-copying information into faster storage system; main memory can be viewed as a last cache for secondary storage. 缓存-把信息复制进较快的存储系统;主存可看作为二级存储器的 最后一个缓存 Applied Operating System Concepts 2.13Applied Operating System Concepts 2.13 Storage Hierarchy 存储层次 • Storage systems organized in hierarchy.存储系统分层组织 – Speed 速度 – cost 成本 – volatility 易失性 • Caching – copying information into faster storage system; main memory can be viewed as a last cache for secondary storage. 缓存- 把信息复制进较快的存储系统；主存可看作为二级存储器的 最后一个缓存