IBM System: A Critical Review of i Disk Storage Capabilities

The internal storage system employed by system i architecture in IBM systems brings out the correct meaning of data storage in computing. Storage under system i architecture involves ensuring that data is protected; ensuring ease of use of data; minimizing the cost of storing data and minimizing maintenance requirements. Moreover, the multiple options that are offered by the system i architecture for integrated disk and tape drives allow for maximum flexibility in data storage.

The numerous hardware functions provided by the system i architecture, allow efficient use of disk space and data protection. Device parity protection is an example of such functions which protects against data loss in case of disk failure or disk damage. The function works by calculating and saving parity value for each bit of data that is entered into a disk. In addition to ensuring that data is not lost, device parity protection allows for high availability of system resources by ensuring that operations are continued despite failure of a disk. Other tools that seek to address disk failure include RAID-5 which comes in handy in case of failure of a single disk unit and RAID-6 which ensures availability in case of failure of two disk units.

Mirroring and cross site mirroring are advanced functions that increase availability of servers in case of disk-related hardware component failure. Mirroring functions are i5/OS operating system functions that allow for duplicating of disk related hardware for instance the bus and disk devices for use in case of failure. Cross site mirroring on the other hand allows for keeping identical copies of data which extends the functionality of device clustered resource groups.
Disk space management is made easy by integrated hardware disk compression functionality. Every time data is written or read from a disk the disk controllers dynamically compress or ‘uncompress’ data. It is important to note that the processes do not affect the use of the CPU. Compression allows effective use of disk space by reducing the volume of data and metadata.