BACKUP AND RESTORE

The main area to be consider when designing a backup strategy Which information should be backed up Which technology should be backed up When and how often should backups occurs

Backup overview  Points to be considered while developing a backup process 1.Ensure recovery from major losses 2.Check backups periodically 3.Keep old backups 4.Check file systems before backing up 5.Ensure files are not in use using backup 6.Backup the system before implementing any major changes

Backup Definition Backup refers to making copies of data so that these additional copies may be used to restore the original after a data loss event. These additional copies are typically called “backups”. Backups are used primarily for two purposes:  To restore a computer to an operational state following a disaster(disaster recovery)  To restore small number of files after they have been accidently deleted or corrupted. Backups are typically the last line of defence against data loss, and consequently the least granular and the least convenient to use

Importance of data backup for business How are data backup services useful? Backup types: 1. Full backup 2. Differential backup, Incremental backup 3. Mirror backup

Full backups ◦full and complete backup of entire system Full Backup Su

Advantages of Full Backup: 1.Restore is the fastest. Disadvantages Of Full Backup: 1.Backing up is the slowest. 2.The storage space requirements are the highest (compared to other backup techniques)

Differential backup -storage of all files that have changed or been added since last full backup

Restoring from Differential Backup

Key Features of Differential backups ◦More files to be backed up, therefore it takes more time to backup and uses more storage space ◦Much faster restore because only the last full and the last cumulative backup must be applied

Advantages of Differential Backup: 1.Restore is faster than restoring from incremental backup. 2.Backing up is faster than a full backup. 3.The storage space requirements are lower than for full backup. Disadvantages of Differential Backup: 1.Restore is slower than restoring from Full backup. 2.Backing up is slower than a incremental backup. 3.The storage space requirements are higher than for incremental backup.

Incremental backups o only archives data that have been modified that day

Incremental backup

Key Features of Incremental backups ◦Files that have changed since the last backup are backed up ◦Fewest amount of files to be backed up, therefore faster backup

Advantages Of Incremental Backup: 1.Backing up is the fastest. 2.The storage space requirements are the lowest. Disadvantages of Incremental Backup: 1.Restore is the slowest.

Mirror Backup o Mirror backup is identical to a full backup, with the exception that the files are not compressed in zip files and they cannot be protected with a password. o A mirror backup is most frequently used to create an exact copy of the backup data. It has the benefit that the backup files can also be accessed using tools like Windows Explorer. o “ A mirror backup is a straight copy of the selected folders and files at a given instant in time.”

Advantages of Incremental Backup: 1.The fastest backup type. 2.It creates the snapshot of the selected files and folders in the destination which you can browse and access later without needing to run backup for all. Disadvantages of Incremental Backup: 1.It needs more storage space than any other backup type. 2.Password protection is not possible. 3.Cannot track different versions of files.

Storage, The base of a Backup System Storage media : data need to be stored on some storage medium. 1.Magnetic tape (for bulk data storage, backup, archiving and interchanging) 2.Hard disk( low access time, availability, capacity and ease of use) 3.Optical disk(restored on any machine with a CD-ROM drive) 4.Floppy disk (obsolete storage medium) 5.Solid state storage (relatively costly for low capacity but offers excellent portability and ease of use) 6.Remote backup service (backing up via internet)

8. managing the data repository 9. On-line 10. Near-line 11. Off-line 12. Off-site vault 13. Backup site,disaster recovery center or DR center

Selection, Extraction and manipulation of data 1.Selection and extraction of File data i.Copying files ii.File system dump iii.Identification of changes iv.Block level incremental v.Versioning file system 2. Selection and extraction of live data i.Snapshot backup ii.Open file backup iii.Cold database backup iv.Hot database backup

3. selection ad extraction of metadata i.System description ii.File metadata iii.Partition layout iv.Boot sector v.Manipulation of data vi.Compression vii.Deduplication viii.Duplication ix.Encryption x.Staging xi.Managing the backup process

Objectives 1.Recovery point objective(RPO): the most desirable RPO would be the point just prior to the data loss event. Making a more recent recovery point achievable requires increasing the frequency of synchronization between the source data and the backup repository. 2.Recovery Time objective (RTO): The amount of time elapsed between disaster and restoration of business functions. 3.Data Security: in addition to preserving access to data for its owners, data must be restricted from unauthorised access. This can be achieved with data encryption and proper media handling.

Limitations System impacts: Cost of hardware, software, labour Network bandwidth Implementation Scheduling Authentication Chain of trust Measuring the process Backup validation Reporting Logging Validation

Restore System restore takes ‘snapshot’ of your computer at regular intervals. The snapshot-more technically, a restore point- incudes the complete registry settings, copies of system files and some programme files and assorted other information. This information is stored in system restore’s data store in a protected folder called _RESTORE.

Restore point types o Initial system checkpoints o System(scheduled) checkpoints o Program name installation restore points o Windows auto update o Manual restore points