In block storage, the data is divided into data blocks of equal size and each is given its own address. In contrast to file storage, the data blocks of block storage are not provided with metadata from which the content of the data can be inferred; they are identified only by their address.
The data of a block storage can be accessed directly with the operating system of the server. A block is uniquely identified by its own block address. When a request is made for a block, the block address is sent to the server of the block storage via the SCSI interface. Fibre Channel( FC) and Serial ATA( SATA) are also used as protocols. The block storage server determines the storage location and restores the data using the storage level function. One difference between file storage and block storage is that block storage data is not divided into data blocks. The retrieval of the data blocks and their combination is handled by the storage management system, which prepares the blocks for the application. If the data blocks are stored in geographically distributed storage systems, then the performance may decrease due to the increasing latency.
As for the file systems, these are based on the type of block storage. This corresponds to the abstraction level of the hardware on which the data blocks are stored in a specific block size. The data block size of the file system can be many times larger than that of the physical memory, but this leads to inefficient use of the physical memory.