A backup is a copy of one or more files created as an alternate in case the original data is lost or becomes unusable. For example, you may save several copies of a research paper on your hard drive as backup files incase you decide to use a previous revision. Better yet, you could save the backups to a USB flash disk, which would also protect the files if the hard drive failed.
Hard drives are meant to run for many years without crashing. But just like all electronic devices, they are not immune to problems. Because they are not solid state devices, hard drives rely on moving parts to access data, which can malfunction and cause your data to become unrecoverable. If you need proof of how fragile hard drives really are, go to your local computer store and have someone show you an open hard drive. When you realize all your data is stored in such a small, delicate device, you may have a new understanding of why you need to backup your data.
But it’s not just hardware malfunctions you have to worry about. Software corruption can also damage your files. Directory structures can become damaged and cause entire folders to disappear. Files can be mistakenly deleted or corrupted by viruses or other software attacks. Program installation conflicts can make applications or files unusable. There are unfortunately many ways for your data to become damaged or disappear.
That is why it is so important to backup your data. Most people don’t realize the importance of having a backup until it is too late. Of course, when you have lost years of photos, school papers, business documents, e-mail archives, music, movies, or any other data that you cannot recover, the importance of having a backup becomes all too real.
So how do you backup your data? The best way is to use an external storage device, such as an external hard drive, flash memory device, or even another computer. You can also create permanent backups using optical media, such as CD-R and DVD-R discs. Backing up individual folders and files is as easy copying them from the source media (your computer’s hard disk) to the destination (an external hard drive). If you want to backup your entire system or would like to have regular backups automatically performed, you can use backup software that will backup your data for you. Many programs are available for both Mac and Windows that provide automatic backups and system restore capabilities.
Types of Backup :-
There are different kinds of backups, the following lists some of them:
1> Full Backup :-
Full backup is the starting point for all other backups, and contains all the data in the folders and files that are selected to be backed up. Because full backup stores all files and folders, frequent full backups result in faster and simpler restore operations. Remember that when you choose other backup types, restore jobs may take longer.
Advantages :- • Restore is the fastest.
Disadvantages :- • Backing up is the slowest. • The storage space requirements are the highest.
2> Incremental Backup :-
Incremental backup means backing up everything that has changed since last full backup.
Advantages :- • Backing up is the fastest. • The storage space requirements are the lowest.
• Restore is the slowest.
3> Differential Backup :-
Differential seems to be another name for incremental.differential backup offers a middle ground by backing up all the files that have changed since the last full backup.
• Restore is faster than restoring from incremental backup. • Backing up is faster than a full backup. • The storage space requirements are lower than for full backup.
• Restore is slower than restoring from full backup. • Backing up is slower than incremental backup. • The storage space requirements are higher than for incremental backup.
4> Network Backup :-
Network backup usually means backing up a client to a backup server, this means the client sends the files to the server and the server writes them to backup medium.
5> Dump Backup :-
Dump backups are not ordinary file by file backups. The whole disk partition or file system is “dumped” to the backup medium as is. This means it is also necessary to restore the whole partition or file system at one go. The dump backup may be a disk image, which means it must be restored to a similar disk with same disk geometry and bad blocks in same places.