Currently Being ModeratedNov 4, 2013 9:51 AM (in response to bd-mac)
Disk Utility really only allows you to create a disk 'image' of your internal drive - somewhat like a snapshot of your drive embedded in stone. Most people, if they are going this 'clone' route, use a clone utility such as Carbon Copy Cloner to create clones that are 'snapshots,' too, but are bootable and can (usually - depending on what type of external drive you have) be used in an emergency should your internal drive fail. A genuine bootable clone is a much better back-up method than using Disk Utility's disk imaging.
Time Machine makes incremental backups - continuous backups (hourly, if you've the TM drive(s) plugged yp) so that you're not far away from avoiding 'missing' any new data.
The best backup methods can be found in ds store's excellent user tip - Most commonly used backup methods.
Currently Being ModeratedNov 4, 2013 10:11 AM (in response to bd-mac)
TimeMachine or Disk Utiliy?
What is the difference between making a backup with one or another?
TimeMachine is a non-bootable automated rotational backup with the option to restore previous versions of files or the entire system so many days back in time depending upon the size of the changes and the available space on the TimeMachine drive. It can only restore, not be used to run the computer.
Disk Utiltiy can do whole parititon cloning only.
Another option is bootable clones + optional saved states, which are exact bootable duplicates of your OS X boot drive/partition on external drives, thus giving the best versatility and reliability for restoring, data recovery or just getting your machine working in seconds even if the boot drive fails mechanically.
The first two are free and included in OS X, the last one is paid software.
See the full monty here
How big can be the created file?
TimeMachine and bootable clones enabling the saved state changes feature need a larger drive than the one being backed up.
Bootable clones that are maintained pure (no saved states) and Disk Utiliy parititon images require a destination that is at least equal to the contents being imaged, even if it's on a smaller parittion or drive.
If the backed-up system has any virus, will be they in the buckup?
Backup systems are just that, backup systems.
They copy corruption, malware and unwanted content just the same.
However with Carbon Copy Cloner, there is a option to exclude unwanted files during the cloning or updating operation, which is another asset of this type of software.
For malware elimination, it's best to backup manually just the known, uninfected files to a external storage drive, then erase the entire boot drive and reinstall OS X, programs and returned/cleaned files from backup. Not restoring anything from TimeMachine or clones. This complicated proceedure is known as a Fresh install method.
Can they affect to the disk or memory where Im doing the buck up?
RAM memory is volitile, once the power goes off the contents of RAM are gone.
Once the boot drive is completely erased, NVRAM reset and the machine is rebooted, any malware should be gone.
However there are other areas where piece of mailcious software can reside, like the keyboard and battery firmare, but supposedly they are not large enough to hold code to reinfect the entire system.
If you suspect your machine has been compromised, seek the services of a local professional.