Backup is to copying files from main storage system or local PCs to backup system or data centre so that they can be preserved in case of equipment failure or data loss. Data loss can occur because of multiple reasons , some one can delete files accidentally, hard disk can crash or some catastrophic event like fire or flood etc.
Backups have two distinct purposes. The primary purpose is to recover data after its loss,The secondary purpose of backups is to recover data from an earlier time.
Type of Backups:
We can divide backup either Structure/Architecture or Geographical
Full Backup is backup where all the files and folders selected for the backup will be backed up again and again. Its slow and takes lot of space but on other hand its efficient and easy at the time of restore.
Incremental Backup Fist backup is always full backup and all subsequent backups runs are just change made since the last backup. Its fast and takes less space to backup but slower than full backup at the time of restore.
Differential Backup First backup is always full backup and all subsequent backups run are just change made since the last Full backup. Its fast and takes less space then full backup. Faster than incremental backup at the time of restore.
Mirror Backup Source hard disk/tapes are back up/mirrored as name suggested. Keep in mind if files or data deleted from source it will be deleted from mirror too.
Local Backup is backup where storage system is kept in same building as source system.
Off site Backup when the backup is kept at different geographical location from the source.
Online Backup typically its off site and usually going on continuously to backed up the source. Usually its connected via Internet or network connection.
Remote Backup it can be offsite or onsite usually connected via network connection or Internet, can be accessed, restore, administrate and managed remotely.
Cloud Backup It can be online or remote backup, usually connected via Internet
Backup Strategy: Regular backups are vital defence against a data loss, system crashed or catastrophic event. Developing a backup plan and strategy is important for businesses as cost and time to recreated or recovered old data is huge.
We will focus our strategy using tapes backup which is ideal for backing because of its high storage , low cost and ability to move to offsite but we may can use same strategy using any virtual , remote or cloud backup. Just replace tape with task.
We will call this strategy CRS, You happliy can use any other name.