Taken from : http://www.macnn.com/reviews/leopard-review:-time-machine.html
Leopard review: Time Machine
October 31st, 2007Time Machine makes backup easy for home users
setting up Time Machine: as simple as possible
Any Mac user who has bought an external hard drive to backup their computer knows that merely setting up a software routine can be complex. Many drive manufacturers only include Windows-based backup software or advertise simple "one-touch" solutions that still requires moderate knowledge during setup so that a scheduled backup routine can function.
Time Machine, by contrast, makes the configuration almost trivial. The setup process is almost completely automatic. When a fresh drive is connected to the system, Time Machine brings up a prompt asking whether or not the drive will be used for backups. If the drive is formatted for Windows (FAT32 or NTFS), the drive must be reformatted before Time Machine will use it for backup. About the only extra detail required is choosing which volumes to exclude from the backup, such as a Boot Camp partition, or drives holding non-essential data..
The initial connection prompt
Excluding drive volumes from the backup
Once setup is complete, Leopard lets you know that it will start out by fully backing up whatever was allowed during setup. This process can take a long time and might disappoint some users who might want to use a small drive for incremental backups, but this is literally the last step. Time Machine handles scheduling on its own, and the schedule can be viewed from with in the System Preference pane. For many, this is the first time when worrying about scheduled backup times is simply a non-issue.
maintaining and restoring backups
This simplicity carries on in daily use: as Apple explains, Time Machine automatically makes short-lived hourly backups, keeps daily backups for the last month, and maintains as many weekly backups as will fit on the chosen backup drive. As long as there is enough headroom on the backup drive, one never has to fret about whether a recent backup exists, outside of the rare chance that the main storage unit dies before the next hourly backup, and a new file has been created within that time span. This automation could be enough to sway users to create backups for the first time or to even consider using Time Machine instead of a more advanced albeit more headache-ridden program.
It is important to note that the drive can be safely removed for transportation or storage, and that Time Machine will resume backups when the drive is reconnected.
Thankfully, Apple's backup implementation only as a small hit on system resources, making it workable for users who might run performance-intensive programs. Time Machine is very selective, only consuming extra space as files are updated in between backups. Unless you work constantly with monolithic files, such as a video project or a program that maintains a large database file – such as a Microsoft Entourage mailbox – the entire backup often takes only a few seconds. Application performance did not diminish in any noticeable way in my testing.
Restoring a backup is painless, if something of a spectacle. Rather than embed the restore view within the Finder, Time Machine opts for the drama of switching to a custom, full-screen interface with a moving star field and windows stretching out into the distance. Files and folders are found just by running a search either in the Finder or a supporting program (such as iPhoto or Mail) and invoking the Time Machine interface. For simply restoring a lost file or an individual folder, it works quite seamlessly; you simply click a back arrow and wait until the software finds the most recent copy of the file in a specified location, or you click a spot on the timeline if you're looking for a specific version. Guesswork is virtually absent, requiring only that you remember part of the name or file contents. Being able to find a lost photo in programs that normally hide file names or metadata is an uncommon benefit, even if the ability to use Time Machine outside of Apple programs is currently non-existent.
Despite how flashy the process is, as opposed to Apple's otherwise consistent Leopard interface, Time Machine's restore process is simple to comprehend, even for novice users. By giving users a literal demonstration of how the concept works by going "back" to retrieve what they need, it presents very little opportunity to restore the wrong file or otherwise make a mistake. While Windows Vista's Previous Versions has its own advantages, which will be addressed shortly, its conventional implementation makes it harder to find files that have disappeared altogether and is likely to scare away inexperienced users who simply want to restore an old Word document or a missing vacation image.
The primary obstacle to widespread adoption of Time Machine is the same reason why some dislike the iPhone (as of October 2007) or the Mac itself: the lack of control. The relatively unprofessional look of Time Machine aside, businesses and high-end users are most likely to be dissuaded by the all-or-nothing approach. There is no way to only backup the Documents folder, for example, or to limit backups of certain items (such as those large mailboxes) to daily or weekly intervals. Any Time Machine drive has to be at least somewhat larger than the total data that needs to be safeguarded, which can be costly for users whose existing storage reaches into the terabyte-plus range.
Likewise, a Time Machine drive is not bootable in and of itself; in the event of a boot drive failure, a user has to first boot from the Leopard DVD and then opt to restore from the backup. This may not be an issue for the average home user, who can usually go one or more days without serious consequences, but could prove disastrous for a professional without a replacement drive in easy reach. Third-party utilities like Shirt Pocket's SuperDuper (which has yet to be updated for Leopard as of press time) will still be a more viable alternative for users who simply cannot afford the downtime.
It also represents a step down from Windows Vista's Previous Versions in that a local, separate drive volume is needed just for Time Machine to work (the AirDisk feature of newer Airport Extreme routers is currently unsupported). While Time Machine can involve a virtual partition rather than a physical drive, the fact remains that Vista users can simply switch back to an old version of a spreadsheet without ever formatting their hardware -- even if they still require a separate solution for mirroring their content outright.
In spite of these shortcomings, Apple has created one of the easiest built-in backup solutions to date, if not one of the easiest solutions of any kind. It may not gain much traction in business, but it should be the first system that can be unreservedly recommended to friends who are just realizing how fragile their information can be, especially for those with the misfortune of learning this first-hand. Any truly safe backup system will cost money, so arguments related to cost are largely moot to begin with since Time Machine is already included with Leopard. What Time Machine does best is to make backup considerably less irritating, and perhaps even fun for those who enjoy astronomy.
Desktop and Finder
Incredibly simple to set up and maintain. Thorough backup stages make it hard to lose a file Cons
Not ideal for large drives. Professionals may be dissuaded by Time Machine's appearance. No configuration options for advanced users.