Printable View
You know that the OS X lion now include new feature called Time machine. Some might have already used it but does anyone know how exactly the Time Machine works in Mac OS X Lion. This is the one feature I still could not able to find out how. So far I know only one than and that is it has two main bits of "Magic" behind Time Machine:
- The File System Event Database -- How changes are found here?
- Multiple Hard Links -- How backups are stored here?
As far as I know that the Time machine on Mac Os X is greatly oversimplified, but here is the thing about how it works:
- To check it yourself, First Create File A and File B, and run an initial backup
- After that delete File A and create file C, and run another
- Now go the backup folders via the Finder, there you will see some kind of illusion happened.
- You will see two copies of File B, but there aren’t. The backup folder contains a version of the contents of your system and it is only at the time of backup. When the system is out of space or low on space, the Time Machine can delete your first backup but the full versions backups remain untouched. All its hard links are deleted but not the actual copies
In Mac OS X Lion, Apple has implemented several changes in Time Machine. From now on the local hard disk which is used at the time the back-up position is not available. Changes you make on your MacBook in a cache folder with the default intervals 1 per hour for the past 24 hours, 1 per day for the past month. This local cache is automatically sent to the Time Machine backup location will move when it becomes available again.
The system is so simple, that simplicity that just turns against the system in one aspect, which in turn becomes the only problem of the method developed by Apple. The only test that makes Time Machine when to back up a file is that this has changed recently, the problem with using this method occurs with large files or databases. Any small change in these files affects an amendment to its creation date and so many kb few can become modified Mb or Gb extra time to keep a copy of those files. Apple is fully aware of the fault and why certain programs were modified to not be affected. When we make a copy of iPhoto Time Machine, do not copy the entire library, only the files you've added or modified. Unfortunately this operation "optimal" only occurs in these programs, not individual files or databases created by us.
When you connect a new disk to Mac OS X Lion to , a message appears asking if you’d like to use the disk to back up your files. Time Machine use this disk(called time capsule) for backups and start automatically backs up your entire Mac. yes but,. It takes incremental backup in which only the files that have been modified since last full back up are backed up. It is a nice backup utility.