defragment and backup?

1) No
2) Yes, Time Machine. System Preferences. Just turn it on and pick a backup drive.

The MacOS's built-in backup facility doesn't give you a full bootable backup (although some diehard Macheads may try to tell you different).

For easy *fully bootable* backups that require no additional work, try the freeware applications SuperDuper or (my preferred) Carbon Copy Cloner

http://www.versiontracker.com/dyn/moreinfo/macosx/13260

Some diehard Time Machine haters will try to create straw men arguments about what Time Machine is and is not (although they will deny it to their dying breath).

Some people don't need a bootable backup. I certainly can see situations where that would be useful. Other people don't need a bootable backup and Time Machine works just fine.

I rest my case.

Yes. Time Machine will grab all of your files and give you hourly, weekly & monthly backups of all of your data.

If your hard drive fails, replace it, reinstall OSX, then restore your data from Time Machine.

or better still: if your hard drive fails and you had made a bootable backup in the way I suggested, you could carry on immediately with your work and would not need to re-install anything (nightmare).

The Mac diehards won't tell you this and will just insult me. I apologise on their behalf.

yes, but it would a lot easier and quicker to clone back from an external drive - assuming you had made a bootable clone before your hard drive died.

Mauricette:

Does Mac OS need to defragment the hard drive?

Apple says you don't in the article About disk optimization with Mac OS X. However, if your HDD is within 80% of total capacity full, it is a good idea. OS X needs a minimum of 15% of total disk capacity free for swap files and growing the directory. However, that 15% needs to be contiguous space. If it is fragmented, or has large fragments, you can end up with overlapping volume structures. That is, if Extents Overflow needs to expand and does not have sufficient contiguous free space extents that currently have data on them may end up having additional pieces of data written to them resulting in directory corruption. So if you are within the 15% range, defragmentation can save you major headaches.

😉 cornelius

Except that you don't have to remember to run a backup with Time Machine and it's out of the box functionality. It doesn't get any simpler to setup and it's the way Apple thinks it should be done.

Time Machine backups are differential, transparent and extremely straight forward.

Yes, Time Machine backs up all of your software & preferences too.