Arnawa Widagda, Contributor, Jakarta
Although most people are aware of the importance of backup data, all too often they do not employ a good backup policy or do not back up enough data. This is true of all nearly all PC users, from the average user to the most tech-savvy ones.
Most people only make backup files after it's too late to do any good. Though the reliability of PCs may have gotten better over the years, hard drive failures are still the second biggest reason for crashes and data loss. With increasing capacity and file sizes, you risk losing more data when the hard drive in your PC fails.
Employing a good, sound backup policy and regularly backing up data is the first, most important step in avoiding data loss -- be it from theft, hardware failure or accidental deletion. Unfortunately, most people do not seem to understand this simple fact. When data loss occurs, they seek to recover data through data recovery software and services. Though it may be successful -- at least in some cases -- data recovery has its limits. Physical damage to hard drives, CDs and DVDs can render the data stored in them completely inaccessible. There is also the likelihood of data corruption. Even the most painstaking recovery and reconstruction methods will not always be able to successfully restore corrupt data.
The first thing that should be considered if you are thinking about employing a backup policy is how much data can you afford to lose? This means you have to differentiate between data you frequently access and change and that which you do not. The frequency of updates will also determine whether you should do daily, weekly or monthly backups. You also might want to prioritize data to documents, e-mails, contact lists and so forth if you do not need a complete backup of everything in your PC.
Now, in general, there are two kinds of backup you can employ: a full backup and an incremental backup. A full backup means you back up all the data you have. This is safer but takes more time. An incremental backup, as the name implies, only backs up changes made after your last backup -- so takes less time but if you lost one incremental backup, you would not be able to recover the backups made after that point.
The best way is to combine both; for instance, do a full backup weekly and incremental backups daily, depending on how frequently you update files and data.
The old saying ""never put all your eggs in one basket"" also applies to backups. Always make at least two copies of backups -- one for archival purposes and one for access. If one backup fails, you will always have another to restore from. Of course, special care should also be taken in storing these backups, ideally you would want to store them in a controlled environment safe from dust, moisture, fire and pests. It is also a good idea to regularly check the state of your backups, making sure they can still be accessed.
To simplify backups, you should use one main folder to store your data. For Windows users, this will likely be the ""My Documents"" folder. As for software, Windows XP Professional actually offers a more robust backup solution than Vista because it lets you select all files and folders, even entire drives. Vista backup features, at least on certain Vista versions like Starter, Home Basic and Home Premium Edition, limit you to certain types of files. There are third-party solutions -- commercial and free -- like DriveImage XML, which offers the same flexibility as Windows XP Backup Utility.
For most people, recordable and rewritable DVDs are the easiest, most affordable form of backup. The difference between recordable and rewritable DVDs is that you can write, erase and rewrite data into rewritable DVDs. They do cost more but its worth it, particularly for incremental backups. However, they do have a limited number of rewrites. For archival purposes, recordable DVDs would be just fine. These DVDs do not take up much space and can be accessed much more quickly than magnetic tapes. Good DVD recordable media costs about US$ 1 a piece, less if you buy them in bulk. Each disc can store up to 4 GBs of data, 8 GBs with dual layer DVDs. Most new desktop and notebook PCs have a built in DVD recorders and you can buy a good one for about $50 if you do not have one.
Another form of advanced data loss protection you can employ is Redundant Array of Independent Disks (RAID), more accurately fault tolerant RAID levels such as RAID 1, 5 and 10. Thanks to technological advancements, these features traditionally found in mission critical workstations and servers can now be found easily on most desktops. Most chipset and motherboard manufacturers offer RAID 0,1,5 and 10 support with a number of their products.
By using two hard drives, RAID 1 or mirroring stores an exact duplicate of data in the second hard drive. So, when one drive fails, RAID will automatically switch to the remaining good drive, hence the term ""mirror"". The downside is that you need two drives with identical capacities -- and performance -- which means the cost per Gigabyte is high. If you use two 250 GBs drives, you can only store 250 GBs of data.
If your PC supports it, RAID 5 offers better cost per Gigabyte and increased storage performance, but you need to use at least three, identical hard drives. Much like RAID 0 or striping, RAID 5 enhances performance by storing different parts of files on two separate drives, thus data is read from and written to much more quickly than if it is stored on a single drive. For fault tolerance, it stores a record of the parity data used to reconstruct files -- if one of the drives used for data storage fails.
Because of the technical complexity and the additional costs of using more than one hard drive, RAID is not for everybody. It is mainly targeted at power users who cannot afford to lose any more than a day's data. However, it is a good alternative for users with more than one computer or a SOHO networked environment. For example, if you and your coworkers or family use notebooks exclusively, you can use a RAID 1 or 5 array on your file server and use it as a backup server as well. Windows Home Server employs a similar strategy for families with more than one computer in the household. With this solution, data in both the server and each notebook or PC gets protected and you can ""spread"" the cost of backups.
Just remember, even with fault tolerant RAID arrays, it is still a good idea to do regular full and incremental backups, at least for archival purposes. RAID arrays do not protect against accidental deletion and overwrites, since it basically only protects data from hardware failures. To avoid such incidents, it is always better to practice basic housekeeping tasks like always using the recycle bin/trash/deleted items for deletion and configure your software to create backup copies when saving. Users with Windows Vista Business, Enterprise and Ultimate Edition can also use its Volume Shadow Copy features to save each incremental change to a file.
