Data Storage

In the ever changing technological world we live in today there are numerous types of physical storage mediums, from magnetic storage devices to optical storage devices and flash memory devices.  So many different mediums to choose from today, and why do you think this may be?  Well we have thousands of devices out there that different by type and age therefore we require many different storage mediums to use with these devices. 

The most commonly used storage mediums are the magnetic storage devices which is non-volatile.  This is the technology currently used in a majority of computers new and old.  The magnetic storage devices are floppy diskette, hard drive, superdisk, tape cassette, and zip diskette.  Honestly only a portion of computers in use today use one of them and that is the hard drive as it is the newest and greatest available of its kind.

Secondly, the next most commonly used storage mediums are the optical storage devices which is non-volatile.  This technology requires a light and laser method to read and write the data.  You will most commonly find these when purchasing and installing software or buying and watching a movie.  The optical storage devices are blu-ray disc, CD-ROM disc, CD-R and CD-RW disc, DVD-R, DVD+R, DVD-RW, and DVD+RW.

Lastly, flash memory which is non-volatile, is up in the running to replace magnetic storage devices considering it is by far cheaper and definitely the most efficient and reliable solution.  The flash memory devices available today are jump drive or flash drive, memory card, memory stick and SSD.  The SSD is a Solid-State Drive or Disk which uses a non-volatile memory to store and access data.  This is very similar to computer RAM considering it does not have any moving parts what so ever. 

There are many different file allocation methods between disks, tape, and flash media; such as contiguous, noncontiguous, indexed, tape, and flash allocation.  Contiguous storage allocation is the method of which storage allocation is assigned to contiguous blocks that are sufficient to hold the file.  Noncontiguous storage allocation is the method of which storage allocation is contiguously changing.  This allows the file to be stored noncontiguously in whichever blocks are available at that point in time.  Indexed allocation is the method of which storage allocation comes down to a separate index block for each and every file.  Tape Allocation is the simplest of them all as the block size can vary to fit logical requirements.  CD, DVD and flash drive storage allocation is based on a standard format of UDF (Universal Data Format).

Even with all the devices available today, there is still the possibility of fragmentation which is a disaster to say the least.  This fragmentation is the circumstance of which files are divided across a disk in pieces.  Sadly, fragmentation occurs naturally when using a disk frequently, whether you are modifying, creating, or deleting files.  The best way to avoid this is by providing regular maintenance and performing a defragmentation task on a regular schedule.

Medium	Methods	Size Constraint
Floppy diskette	FAT12	1.2 MB
Hard Drive	FAT 32, NTFS	10 TB +
SuperDisk	FAT16B	120 MB
Tape cassette	Linear Tape-Open	10 TB +
Zip diskette	NTFS & FAT	250 MB
Blu-ray disc	UDF	25 – 50 GB
CD-ROM disc	UDF	650 – 700 MB
CD-R and CD-RW disc	UDF	650 – 700 MB
DVD-R, DVD+R, DVD-RW, and DVD+RW disc	UDF	1.5 – 5 GB
Jump drive and flash drive	UDF	2 GB – 1 TB
Memory card	FAT12, FAT16, FAT32, exFAT	2 GB – 2 TB
Memory stick	NTFS & FAT32	4 MB – 256 GB
SSD	FAT32 & NTFS	50 GB +

References

Englander, I. (2014). The Architecture of Computer Hardware, Systems Software, & Networking An information technology approach. Don FowleY.

Storage Device. (n.d.). Retrieved March 18, 2017, from Computer Hope: http://www.computerhope.com/jargon/s/stordevi.htm