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Backing up data
What is backing up of data?
Backing up refers to the copying of files and data to a different medium, in case of a problem with the main storage device.
Backing up files and data on a regular basis is seen as good computing practice and many computer systems can be set to back up files automatically on a regular basis.
The backups are often stored in a different place to the main storage.
Why back up data?
-Data could be lost due to failure of the original storage device.
-Hackers could be responsible for the corruption or even loss of data.
-Backups are also made in case the files need to be used elsewhere.
What is backing up of data?
Backing up refers to the copying of files and data to a different medium, in case of a problem with the main storage device.
Backing up files and data on a regular basis is seen as good computing practice and many computer systems can be set to back up files automatically on a regular basis.
The backups are often stored in a different place to the main storage.
Why back up data?
-Data could be lost due to failure of the original storage device.
-Hackers could be responsible for the corruption or even loss of data.
-Backups are also made in case the files need to be used elsewhere.
![Picture](/uploads/5/8/5/9/58596443/5794787_orig.jpg)
Serial access
![Picture](/uploads/5/8/5/9/58596443/3298930_orig.png)
Direct access
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Backing storage media
Backing storage devices are either internal or external to the computer, and are one of three types:
+magnetic
+optical
+solid state
Backing storage devices are either internal or external to the computer, and are one of three types:
+magnetic
+optical
+solid state
![Picture](/uploads/5/8/5/9/58596443/6492491_orig.jpg)
Fixed hard disk
Fixed hard disk drives are available on all computers and are the main method used for data storage.
-Uses:
Fixed hard disk drives are available on all computers and are the main method used for data storage.
-Uses:
- Fixed hard drives are used to store the operating system and working data.
- Storing applications software that needs fast retrieval and storage of data.
- Real-time systems and online systems used fixed hard drives.
- Used in file servers for computer networks.
- Fast data transfer rate and fast access times to data.
- Very large memomy capacities
- They can be fairly easily damaged.
- They lack portability unless a portable hard disk drive is used.
![Picture](/uploads/5/8/5/9/58596443/3703176.jpg?1444225031)
Portable hard disk drives
This device works in much the same way as fixed hard disk drives but it is usually connected to the computer via a universal serial bus (USB)
-Uses:
This device works in much the same way as fixed hard disk drives but it is usually connected to the computer via a universal serial bus (USB)
-Uses:
- Can be used as back-up systems to prevent the data from losing.
- Used to transfer data, files and software between computers.
- Data access time and data transfer rate is really fast.
- Large memory capacities.
- Used as a method of transferring information between computers.
- Can be easily damaged if the user drops it or shut it down incorrectly after use.
![Picture](/uploads/5/8/5/9/58596443/2452034.jpg?1444276365)
Floppy disk drives
They consist of a thin disk of plastic which is housed in a plastic case with a window where the disk can be accessed. When the disk rotates, a read/write head is used to add or read data stored on surface.
-Uses
They consist of a thin disk of plastic which is housed in a plastic case with a window where the disk can be accessed. When the disk rotates, a read/write head is used to add or read data stored on surface.
-Uses
![Picture](/uploads/5/8/5/9/58596443/2572443_orig.png)
Magnetic tapes
A very thin strip of plastic which is coated in a magnetic layer. Read and written to by a read/write head. The data is stored in magnetic areas which represent 1s and 0s. Data is written to and read from the tape in sequence.
-Uses:
A very thin strip of plastic which is coated in a magnetic layer. Read and written to by a read/write head. The data is stored in magnetic areas which represent 1s and 0s. Data is written to and read from the tape in sequence.
-Uses:
- Magnetic tapes are used in applications where batch processing is used, bank checks, utility billing.
- They are used as a back-up media since all the data needs to be stored.
- Less expensive than the equivalent-capacity hard disk.
- Robust technology
- The data transfer rate is fast.
- Access time is very slow.
- When update, another tape is needed.
![Picture](/uploads/5/8/5/9/58596443/6383289_orig.jpg)
Optical storage media
Optical storage devices save data as patterns of dots that can be read using light. A lazer beam is the usual light source.
Optical storage devices save data as patterns of dots that can be read using light. A lazer beam is the usual light source.
![Picture](/uploads/5/8/5/9/58596443/3467534_orig.jpg)
CD-ROM and DVD-ROM
-Uses:
-Uses:
- CD-ROMs are used by manufacturers to store music files and software.
- DVD-ROMs have a larger storage capacity than CD-ROMs and they are used to store films.
- Hold more data than floppy disks, so one CD/DVD could replace several floppy disks.
- Less expensive than hard disk drive systems
- Data transfer rate and data access time are slower than hard disks.
![Picture](/uploads/5/8/5/9/58596443/2298535_orig.png)
CD-R and DVD-R
-Uses:
-Uses:
- CD-Rs are used for home recordings of music.
- DVD-Rs are used for recordings of films.
- They are used to store data to be kept for later use or transfer to another computer.
- They are used in applications where it is necessary to prevent loss of important data.
- Cheaper than RW disks.
- Once burned, they are like ROM disks.
- Can only be recorded once, so if an error occurs then the disk has to be thrown away.
- Not all CD/DVD players can read CD-R/DVD-R/
![Picture](/uploads/5/8/5/9/58596443/9115870_orig.jpg)
CD-RW and DVD-RW
-Uses:
-Uses:
- They are used to record radio and television programs, but can be recorded over time again.
- They are used in close circuit television systems.
- They can be reused many times.
- They can use different file formats each time they are used.
- The RW format is not as wasteful as the R format since files or data can be added at later stage.
- They can be relatively expensive media.
- It is possible to accidentally overwrite data.
![Picture](/uploads/5/8/5/9/58596443/6094897.jpg?1444279416)
DVD-RAM
-Uses:
-Uses:
- DVD-RAMs are used in recording devices such as satellite receivers to allow consecutive recording and playback.
- They are used in camcorders to store films.
- Have a long life - minimum life is about 30 years.
- It is possible to rewrite operation over 100,000 times, compared with the RW format which only allows about 1,000 rewrites.
- Writing on DVD-RAMs is very reliable, as they have in built verification software to ensure the accuracy of the data.
- Access is very fast if the files are fairly small.
- No need to finalize the disk.
- They have a very large capacity.
- They offer the ability to read data at the same time as data is being written.
- DVD-RAMs are not as compatible as R or RW format, as many systems will not recognize their format.
- They are expensive, 4 times as much as a DVD-RW disk.
![Picture](/uploads/5/8/5/9/58596443/1733806_orig.jpg)
Blu-ray disks
-Uses:
-Uses:
- Used in home video consoles.
- Used for storing and playing back films.
- PCs can use this technology for data storage or backing up hard drives.
- Camcorders can use this media to store film.
- Very large storage capacity, idealistic for storing high definition films.
- Data transfer rate is very fast.
- Data access speed is also greater than others.
- Relatively expensive
- At the time of writing, blu-ray systems still have encryption problems when used to store video.
![Picture](/uploads/5/8/5/9/58596443/8057766_orig.jpg)
Solid state backing store
-Solid state technology is being developed to the point where solid state drives will soon replace hard disk drives in laptop computers.
-Solid state basically means no moving parts.
-Solid state technology is being developed to the point where solid state drives will soon replace hard disk drives in laptop computers.
-Solid state basically means no moving parts.
![Picture](/uploads/5/8/5/9/58596443/8454352_orig.jpg)
Memory stick/pen drives
Can store several Gbytes of data and use the solid state technology described above.
-Uses:
Can store several Gbytes of data and use the solid state technology described above.
-Uses:
- Used for transporting files between computers or as a back up store.
- Used as a security device.
- Very compact and portable media.
- Very robust.
- It is not possible to write protect the data and files.
- Their small physical size means that they are easy to lose.
![Picture](/uploads/5/8/5/9/58596443/7956609_orig.jpg)
Flash memory cards
These are a form of electrically erasable programmable read only memory (EEPROM).
-Uses:
These are a form of electrically erasable programmable read only memory (EEPROM).
-Uses:
- Used to store photos on digital cameras.
- Mobile phones use them as memory cards.
- Used in MP3 players to store music files.
- Used as a back up store in portable computer devices.
- Very compact, easily removed and used in another device or used for transferring photos directly to a computer or printer.
- Very robust because they are solid states.
- Expensive compared to hard drive disks.
- They have a finite life in terms of the number of times they can be read from or written to.
- Have a lower storage capacity than hard disks.