What is a computer backup and how to backup files

A backup is a copy of data for the purpose of easy restoration if it is lost. Data is stored in files. Files are stored on the hard drive disk. The hard drive disk is installed on the computer. When people  back up their computer, what they are actually doing is backing up contents of the computer’s hard disk drive, so they’re making a copy of the information on their hard disk to another location like an external drive or online cloud storage.

The truth is that hard drives always fail; it is just a question of when. Most people do not backup as often as they should or they have a vague idea of what to back up, or they have never even thought to back up at all. As a result, they end up losing data even if they do have some kind of backup system set up. Companies often leave worries of backing up to the employees. Who knows what will happen when disaster strikes? Backup plan must be set to insure safety of valuable data no matter what happens.

You can back up a few selected files or folders or make an exact copy of an entire hard disk drive. A typical selection of files for backup includes folders (default for Windows Backup): My Documents, My Pictures, My Music, My Videos, and Downloads. In order to backup Outlook 2010 e-mails and addresses Outlook Files folder with .pst file must be selected.

Backing up is not always the same as copying. Copying means creating an exact copy of data. Copied data is ready to use immediately. But backup software usually compresses data during the backup and places it in a backup archive. You need the same backup software to retrieve the data. For example: You use Microsoft Backup and Restore. If your computer drive crashed you would need to run Microsoft Backup and Restore to retrieve the data from Windows Backup. You could not just copy files from Windows Backup archive. You cannot start your computer from a backup archive. Same applies to Apple MacTimeMachine. If you want to backup as copy, a script can be written using free built-in system commands, such as robocopy for Windows 7.

Making an exact copy of an entire hard disk drive is called cloning the drive. Cloning can be done to an image (a file) or another hard drive. Cloning a drive is faster than copying all files on the drive. If your system drive is cloned, you can restore the system almost immediately from the hard drive image with all the settings and programs intact. Conversely, backing up files requires your operating system and programs to be installed again. In this respect, cloning is more time and cost effective for recovery after disaster strikes.  The most popular cloning software is: Norton Ghost and Acronis True Image.

Microsoft Backup and Restore and Apple Mac’s Time Machine can back up data files and program and system settings, yet they require the operating system to be reinstalled from the original installation disks prior to recovery.  Systems recovered from such backups are not exactly the same as the originals.

Files backup Disk backup (cloning)
Need to know what to backup Yes No
Ready to run system immediately after failure No Yes
Need a backup software Not necessary Yes
Time needed for recovery More Less
Space needed Less More
Cloud backup Yes No

Backup to cloud is much slower than backup to external usb drive and not practical with large amounts of data because internet connection speeds are significantly slower than a USB connection to a backup drive. Example: an ADSL + internet connection typically has 1MBit/s upload (not download!) speed. Usually the upload speed is limited by the ISP. That is 125kb/s or over 200 times slower than a USB backup drive (typically 30Mb/s). That means that backing up 1 GB of data will take 30 seconds to a USB backup drive and over 1 and a half hours for complete backup to cloud via ADSL+ connection! Of course when incremental backups are set up you are backing up only the recently changed files, so if you only work on a few small text files it would take a minute to update your cloud backup but you might wait for a few minutes when working on large graphic files like pictures. Forget about backing up movies to cloud. This will get better after the upgrade of Australian internet to super-fast broadband. Yet, as it is planned, NBN’s upload speed will still be 5x times slower [1] (40 times faster than ADSL) than today’s USB hard drive connection.

At one data recovery job I did,  a small business owner decided to setup Microsoft Office 365 by himself and transfer e-mails from MS Exchange Server to Microsoft Office 365 cloud service. But he did not realize how long setup of MO 365 would take and that such an operation could fail. A day long data transfer process was interrupted and he lost few years’ worth of business correspondence as a result. Microsoft (and other companies providing cloud based services) does not guaranty the safety of your data due to network problems.

Backup to a local network drive such as NAS or media center is often slower in comparison to a USB connection too. Typically, a local network is 100Mbps which is a few times slower than USB. 1000Mbps or 1Gbps is theoretically faster but is slower in practice.

Naturally, you want your stuff backed up automatically without worrying about it. Windows and Mac do have automated file backup systems built-in. But they are not on by default. Brand new computers can nag you to setup a backup but people often ignore the warnings. This can be especially dangerous to small business owners. Some manufacturers such as Dell bundle new computers with a third party backup software which is not only annoying but useless; this software can slow down the computer and pose security risks. Often an external backup drive is purchased and connected but is set up incorrectly, so people think they have a backup but they really do not.

[1] http://www.nbnco.com.au/rollout/about-the-nbn/network-features.html retrieved 22.11.12


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