TK
Organisational Systems Security
Use of Backups
Explain
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Another way that systems and data can keep secure is by using backups, and regularly backing up a system with data on. This is keeping the information secure because it means that there will be another copy of the data from the system available if the main data is lost in anyway. There are two types of backups; this is differential backups and incremental backups. Differential backups are backups which change all of the data since the last backup was written. The incremental backups changes only the data that has been changed, for example if the data has changed since Monday and it is now Tuesday then only that data that has been changed on Monday will have changed and the rest will stay the same. Incremental backup is constant and will happen every so often such as hourly or every 30 minutes whereas differential backups are done nightly or weekly. This is typically done every night in a business environment. One way that this can be done is through RAID, which stands for Redundant Array of Independent Disks. This is a way that multiple hard disks can store the same data. The reason why this is done is because it means that if one hard disk goes down or gets corrupted then there will be another hard disk that has the same data, meaning nothing gets lost. It does this by employing a technique called disk mirroring, also known as RAID 1. This is the duplication or replication of data which is placed on two or more of the hard disks. Another technique known as disk striping can be used, also known as RAID 0, which is the separation of data between partitions of many different disk drives. It puts the data into blocks, and the data is not duplicated meaning no data redundancy appears here. RAID 2 uses striping, as just mentioned, across a lot of different disks however, it also stores disks used for error checking and correcting. Some disks will purely store information just for ECC (Error checking and correcting). RAID 3 uses the techniques of
Example
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Relating this back to my case study, Vodafone will use backups and it would most likely use incremental backups and the reason for this is because their data is very important to them, therefore they would probably need backups to be processed constantly. They would most likely use on-site and off-site backups storage so that if the on-site ones do not work then they would have a backup of the backup. They would also use physical backups so that they have full control over their data and backups, instead of using a third-party organisation. Vodafone would back up quite regularly. For example, If 30 new customers registered with Vodafone over the course of an hour, then an incremental backup (which could backup every hour) would backup the new customer data and would save it to their on-site and off-site physical backup mediums. This would allow all data to stay intact if the main storage medium was to unexpectedly stop working.
stripping again and has a dedicated disk which is used to store parity information. This will make sure that all information on the disks are correct and have not malfunctioned or been manipulated and the ECC information is stored in this disk. It employs data recovery by calculating OR (XOR) information on the other disk drives employed on the network. RAID 4 uses bigger stripes which mean that data and records can be ready from any disk. It also means overlapped I/O for reading data can be used. The write operations are used to update the drive used for parity information. RAID 5 uses disk stripping with parity, and this means that data and parity information is split across the entire disks that are being used in the configuration. Data can be reconstructed if a disk fails and it also means that read and write operations can be completed over multiple drives. At least three drives are used in this configuration. Redundancy is often seen in the RAID configuration of drives and this is because of the fact that the drives will often copy each other’s data. It is the repetition of data but it is positive because it safeguards data and it keeps data consistent. Backups can be stored both on-site and off-site. When referring to off-site, this means that backups are stored away from the location of where the data comes from and when referring to on-site, it means that the backups are located within the building of where the data is coming from. For example, there could be a server in another part of England where backups are stored, or it could be in Vodafone’s head office. There are also two types of backup locations, apart from on-site and off-site, which can either be physical backups or cloud backups. Physical backups are where the backups are stored on a server which belongs to the company and this means that if the server becomes corrupted in any way then the data would be lost. Cloud backups are when data is copied or saved to an online backup service, which is usually hosted by a third-party company which uses servers off-site to store the data. In businesses, the server would be proprietary.