Logical disk
RAID Recovery - Logical disk
Logical disk is a device that offers data storage area on one or more physical disk drive components in a computer system. Partition, logical volume and virtual disk are some different terms that express similar meaning to it. Logical disk can also be regarded as a new interface to disk storage that separate disk as well as file management.
It was given the name Logical because it doesn’t exist as a single physical entity. Most advanced Operating systems offer some form of Logical volume management which helps with the creation and management of logical volume.
Logical disk can be defined at multiple levels in the storage infrastructure stack.
1. Operating system: It defines the various partitions on the disk to which operating system is noticeable.
2. Storage Subsystem: Generally, It offers various forms of RAID where Logical disks are presented to the SAN but the RAID actually contains physical disks.
3. SAN (Storage Area Network): If the SAN is virtualized, the device in that shows logical disk to the host operating system.
Need of Logical disks:
In 1956, when IBM launched magnetic disk drive, a single drive could be directly attached to the using system, with every disk managed as a single entity. With the gradual development, its reliability problem occurred and RAID technology came into existence. So, to create a single disk, two or more disks need to be RAID-ed together.
In recent times, disk drives are capable of providing hundreds of gigabytes of storage ability in the PC. However, most of the recent systems have their own partitions into various logical drives. In the IT business environment, some form of a SAN can be present. Here, in a network, several storage devices are connected to many host server devices. A single array can distribute capacity between the servers. So, logical disks are commonly used to divide the exited avaiable capacity and offer every host’s storage requirement from different genre of logical disks.
