Components of Storage System Environment

Upon completion of this lesson, you will be able to:

•Describe the three components of storage system environment

–Host, Connectivity and Storage

•Detail Host physical and logical components

•Describe interface protocol

–PCI, IDE/ATA and SCSI

•Describe storage options

–Tape, optical and disk drives

Host
•Applications runs on hosts


•Hosts can range from simple laptops to complex server clusters


•Physical components of host
–CPU
–Storage


•Disk device and internal memory
– I/O device


•Host to host communications
–Network Interface Card (NIC)


Host: Logical Components 

• Application

– Interface between user and the host

– Three-tiered architecture

• Application UI, computing logic and underlying databases

– Application data access can be classifies as:

• Block-level access: Data stored and retrieved in blocks, specifying the LBA

• File-level access: Data stored and retrieved by specifying the name and path of files

• Operating system

– Resides between the applications and the hardware

– Controls the environment

Storage: Medias and Options

• Magnetic Tape

– Low cost solution for long term data storage

– Limitations

• Sequential data access, Single application access at a time, Physical wear and tear and Storage/retrieval overheads

• Optical Disks

– Popularly used as distribution medium in small, single-user computing environments

– Write once and read many (WORM): CD-ROM, DVD-ROM

– Limited in capacity and speed

• Disk Drive

– Most popular storage medium with large storage capacity

– Random read/write access

• Ideal for performance intensive online application