Backup as you all know is a process of taking a copy of your important data. Its importance is not known till someone faces the “dark side” (storage media crash). Investment on backup is wise and it will payback on a disaster situation.

Backing up of data once is not sufficient you need to back it up periodically or when ever the data changes. There are various methodologies, tools for backing up one’s data, lets look into those.

Backup methodologies

Full backup

Backup: This method involves taking full copy of the data periodically.

Restoring: involves taking latest copy of backup and restoring it.

Advantages: Fast restoration

Disadvantage: Uses lot of storage and slow backup

File syncronisation

Backup: This method involves taking full copy of the data once and using some algorithm to syncronize the data with the backup. Here, full data is not copied on every periodical backup.

Advantaages: Faster restoration

Disadvantage: stores only one copy so only can restore to a single version back in time.

Incremental Backup

Backup: This method involves taking a full backup once and creating incremental data periodically. What i mean by incremental data is lets say we have “ABC” in a file called f1. On full backup we store f1 with “ABC” on subsequent backup the file is changes to “ABCD” so we will store on say “4:D”. meaning, need to add D @ position 4. This is just an example actual differential information differs with algorithm used.

Advantages: Fast backup, uses less storage

Disadvantages: Slow restoration because need to restore the full backup and run all the corresponding differential backup over this.

Differential Backup

Backup: This method involves capturing all file changed since last full backup and storing them even thought they where captured in last run.

Advantages: faster restoration when compared to incremental backup

Disadvantages: slower backup speed and uses more space than incremental backup

Various Storage Media for Backup

for desktop usage i think storing the backup data can be done in any one of the following media

Optical media

now, the cost of CD Writers, DVD writers have gone down considerably and we can use the cheap optical media to store the data. When is say optical media there are two types of optical media CD-R, DVD-R and CD-RW, DVD-RW. Earlier is write once media and the later is multi write media.

Advantages:

• Cheap

Disadvantages:

• Needs organisation of the media

• Can store only 650MB/disk in case of CD-R and 4.5GB in case of DVD-R.

• Speed of storage/retrieval is moderate to slow

External Harddisk

Cost of external USB/ESATA hard disks have gone down and using this as an alternative is also good option.

Advantages:

• prices sliding and moderate per GB cost

• Faster storage/retrieval speed

• no need to organising like in case of optical media unless your data spans multiple disks

Consumer grade NAS (Network Attached Storage)

These are device which are connected to network directly and provides storage to all the system in network. They typically use either CIFS (for Windows) or NFS (for Linux).

Advantages:

• Allows backing up of data from multiple system with ease

• Moderate speed

Disadvantages:

• Slightly costlier than External harddisk.

• Needs more hardware like network switch etc to setup

Managed backup service

This is the hottest of the lot. You store you data in remote server provided by backup service provider.

Advantages:

• Very useful in case of natural calamity (your data can be far away from you)

Disadvantages:

• Need decent network bandwidth to/from the network storage provider.

Various Backup Softwares

• Nero Burning Rom with backup to CD/DVD – Windows – (free if came bundled with you CD/DVD writer) - $80 one time

• Norton 360 – Security software with backup feature – Windows - $80/year

• Apple Time Machine – OS-X – part of Apple OS-X 10.5

• Windows Live One Care – Windows - $50/year

• VentisPro Dedicated backup software – Windows - $59

• Backup4All – Windows - $20 - $50

• Areca Backup – Windows / Linux – FREE

• Cobian – Windows – FREE

• Flyback (look alike of Apple time machine) – Linux – FREE

What are you waiting for? Backup your stuff now if you are yet to start.