Advantages
Magnetic disks support direct access of data making them more suitable for a wider range of applications as compared to magnetic tapes, which support only sequential access of data.
Due to random access property, computers often use magnetic disks as a shared device, which is shared simultaneously by multiple users. For example, a computers often use Winchester disks and disk packs as on-line secondary storage devices storing data of multiple users of a computer system. A tape is not suitable for such type of usage due to its sequential-access property.
Magnetic disks are suitable for both on-line and off-line storage of data. For example, Winchester disks and disk packs are often used as on-line secondary storage devices whereas; floppy disks and zip disks are used as off-line secondary storage devices. In fact, high-capacity Winchester disks have made it possible for today's most personal computer users to enjoy the convenience of having all data software readily accessible at all times.
Except for fixed type Winchester disks, storage capacity of the other magnetic is virtually unlimited because as many disks as required can be used for storing very large data sets.
Due to their low cost and high data recording densities, cost per bit of storage is low for magnetic disks. An additional cost benefit comes from the fact that we can erase data on a magnetic disk and reuse it many times.
Due to their compact size and high data recording densities, they enable storage of very large amount of data in a small storage space.
Zip disks are easily portable, and users often use them to transfer data and programs between two unlinked computers.
Data access rate for a magnetic disk system is normally much superior to a tape system.
Magnetic disks are less vulnerable to data corruption due to careless handling or unfavourable temperature and humanity conditions than magnetic tapes.
Although magnetic disks are usable for both random and sequential data processing applications, their usage for sequential applications is less efficient than magnetic tapes.
It is more difficult to maintain security of information stored on magnetic disks used as shared, on-line secondary storage devices as compared to information stored on magnetic tapes or on other types of magnetic disks.
For Winchester disks, a disk crash or drive failure often results in loss of entire data stored on it. It is not easy to recover the lost data. Hence, data stored on winchester disks requires suitable backup procedures.
Some types of magnetic disks, such as disk packs and Winchester disks, are not portable as easily as magnetic tapes.
On cost-per-bit cost of magnetic disks is low, but the cost of magnetic tapes is even lower.
Magnetic disks must be stored dust-free environment.
We must label Zip disks and disk packs properly and logically to remember what data is on which disk/disk pack, and to prevent eraser of useful data by mistake.