<Dl> <Dt> Magnetic tape </Dt> <Dd> Magnetic tape has long been the most commonly used medium for bulk data storage, backup, archiving, and interchange . Tape has typically had an order of magnitude better capacity - to - price ratio when compared to hard disk, but recently the ratios for tape and hard disk have become a lot closer . There have been a variety of formats, many of which are proprietary or specific to certain markets like mainframes or a particular brand of personal computer . However by 2014 LTO was edging out the two other remaining viable "super" formats--IBM 3592 (now also referred to as the TS series) and Oracle StorageTek T10000, and further development of the smaller - capacity DDS format had been canceled . Tape is a sequential access medium, so even though access times may be poor, the rate of continuously writing or reading data can actually be very fast . Some new tape drives are even faster than modern hard disks . </Dd> <Dt> Hard disk </Dt> <Dd> The capacity - to - price ratio of hard disks has been improving for many years, making them more competitive with magnetic tape as a bulk storage medium . The main advantages of hard disk storage are low access times, availability, capacity and ease of use . External disks can be connected via local interfaces like SCSI, USB, FireWire, or eSATA, or via longer distance technologies like Ethernet, iSCSI, or Fibre Channel . Some disk - based backup systems, including Virtual Tape Libraries, support data deduplication--which can dramatically reduce the amount of disk storage capacity consumed by daily and weekly backup data . One main disadvantage of hard disk backups vis - a-vis tape are that they are more easily damaged, especially while being transported (e.g., for off - site backups); however a rugged enclosure may make them somewhat more shock - proof . Another main disadvantage is that over a period of years the stability of hard disk backups is shorter than that of tape backups . </Dd> <Dt> Optical storage </Dt> <Dd> Recordable CDs, DVDs, and Blu - ray Discs are commonly used with personal computers and generally have low media unit costs . However, the capacities and speeds of these and other optical discs have traditionally been lower than that of hard disks or tapes (though advances in optical media are slowly shrinking that gap). Many optical disk formats are WORM type, which makes them useful for archival purposes since the data cannot be changed . The use of an auto - changer or jukebox can make optical discs a feasible option for larger - scale backup systems . Some optical storage systems allow for cataloged data backups without human contact with the discs, allowing for longer data integrity . </Dd> <Dt> Solid state storage </Dt> <Dd> Also known as flash memory, thumb drives, USB flash drives, CompactFlash, SmartMedia, Memory Stick, Secure Digital cards, etc., these devices are relatively expensive for their low capacity in comparison to hard disk drives, but are very convenient for backing up relatively low data volumes . A solid - state drive does not contain any movable parts unlike its magnetic drive counterpart, making it less susceptible to physical damage, and can have huge throughput in the order of 500Mbit / s to 6Gbit / s . The capacity offered from SSDs continues to grow and prices are gradually decreasing as they become more common . </Dd> <Dt> Remote backup service </Dt> <Dd> As broadband Internet access becomes more widespread, remote backup services are gaining in popularity . Backing up via the Internet to a remote location can protect against some worst - case scenarios such as fires, floods, or earthquakes which would destroy any backups in the immediate vicinity along with everything else . There are, however, a number of drawbacks to remote backup services . First, Internet connections are usually slower than local data storage devices . Residential broadband is especially problematic as routine backups must use an upstream link that's usually much slower than the downstream link used only occasionally to retrieve a file from backup . This tends to limit the use of such services to relatively small amounts of high value data . Secondly, users must trust a third party service provider to maintain the privacy and integrity of their data, although confidentiality can be assured by encrypting the data before transmission to the backup service with an encryption key known only to the user . Ultimately the backup service must itself use one of the above methods so this could be seen as a more complex way of doing traditional backups . </Dd> <Dt> Floppy disk and its derivatives </Dt> <Dd> During the 1980s and early 1990s, many personal / home computer users associated backing up mostly with copying to floppy disks . However, the data capacity of floppy disks failed to catch up with growing demands, rendering them effectively obsolete . On the other hand, the larger data capacity of subsequently - developed "superfloppy" devices--as well as a related "non-floppy" device--kept them useful for backing up far longer . In fact the Windows variant of one backup application as of 2017 still permits the use of such "removable disks" as a storage medium, even though the devices that use them are no longer manufactured . </Dd> </Dl> <Dd> Magnetic tape has long been the most commonly used medium for bulk data storage, backup, archiving, and interchange . Tape has typically had an order of magnitude better capacity - to - price ratio when compared to hard disk, but recently the ratios for tape and hard disk have become a lot closer . There have been a variety of formats, many of which are proprietary or specific to certain markets like mainframes or a particular brand of personal computer . However by 2014 LTO was edging out the two other remaining viable "super" formats--IBM 3592 (now also referred to as the TS series) and Oracle StorageTek T10000, and further development of the smaller - capacity DDS format had been canceled . Tape is a sequential access medium, so even though access times may be poor, the rate of continuously writing or reading data can actually be very fast . Some new tape drives are even faster than modern hard disks . </Dd> <Dd> The capacity - to - price ratio of hard disks has been improving for many years, making them more competitive with magnetic tape as a bulk storage medium . The main advantages of hard disk storage are low access times, availability, capacity and ease of use . External disks can be connected via local interfaces like SCSI, USB, FireWire, or eSATA, or via longer distance technologies like Ethernet, iSCSI, or Fibre Channel . Some disk - based backup systems, including Virtual Tape Libraries, support data deduplication--which can dramatically reduce the amount of disk storage capacity consumed by daily and weekly backup data . One main disadvantage of hard disk backups vis - a-vis tape are that they are more easily damaged, especially while being transported (e.g., for off - site backups); however a rugged enclosure may make them somewhat more shock - proof . Another main disadvantage is that over a period of years the stability of hard disk backups is shorter than that of tape backups . </Dd> <Dd> Recordable CDs, DVDs, and Blu - ray Discs are commonly used with personal computers and generally have low media unit costs . However, the capacities and speeds of these and other optical discs have traditionally been lower than that of hard disks or tapes (though advances in optical media are slowly shrinking that gap). Many optical disk formats are WORM type, which makes them useful for archival purposes since the data cannot be changed . The use of an auto - changer or jukebox can make optical discs a feasible option for larger - scale backup systems . Some optical storage systems allow for cataloged data backups without human contact with the discs, allowing for longer data integrity . </Dd>

Where does the location of auto backup data files defined