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Read the following two articles to understand why the solutions that are available for UNIX/Linux don't completely work in Mac OS X:

The State of Backup and Cloning Tools under Mac OS X/
Mac Backup Software Harmful

The simple fact of the matter is that rsync (for example) simply doesn't copy everything. It might be good enough for some backup purposes, but not for a complete backup that preserves everything.

Add to the problem that HFS+ doesn't support any kind of hard link (pre-Tiger) so you can't use an HFS+ partition for incremental backups the way you can with a UNIX/Linux filesystem with hard links. Maybe you can with a UFS partition.

I'm personally very happy that Apple is releasing Time Machine, so that I can finally feel as secure about my backups as I do on my Linux machine. I bet OS X admins are pretty happy, too. But I'm just not as impressed with Time Machine considering how long OS X has been missing an adequate incremental backup solution. It's nothing revolutionary, its just something that is essential that was missing before.

Read the following two articles to understand why the solutions that are available for UNIX/Linux don't completely work in Mac OS X:

The State of Backup and Cloning Tools under Mac OS X/
Mac Backup Software Harmful

The simple fact of the matter is that rsync (for example) simply doesn't copy everything. It might be good enough for some backup purposes, but not for a complete backup that preserves everything.

Add to the problem that HFS+ doesn't support any kind of hard link (pre-Tiger) so you can't use an HFS+ partition for incremental backups the way you can with a UNIX/Linux filesystem with hard links. Maybe you can with a UFS partition.

I'm personally very happy that Apple is releasing Time Machine, so that I can finally feel as secure about my backups as I do on my Linux machine. I bet OS X admins are pretty happy, too. But I'm just not as impressed with Time Machine considering how long OS X has been missing an adequate incremental backup solution. It's nothing revolutionary, its just something that is essential that was missing before.

SuperDuper! is cheap and effective. [shrug]

Currently it's downloadable for under $30US. It's also been shown by one tester to be the most effective backup software for OSX at preserving all data. (Aside from dd, of course.) It's aimed at non-technical users, and those are a significant slice of the OSX user population.

So yeah, I think it's worth paying for and I recommend it unreservedly. While dd may be better for some, they're not the ones asking me for backup software recommendations.

(Like Mr. Jones, I'm also not affiliated with shirt pocket in any way other than being a satisfied customer.)

SuperDuper! is cheap and effective. [shrug]

Currently it's downloadable for under $30US. It's also been shown by one tester to be the most effective backup software for OSX at preserving all data. (Aside from dd, of course.) It's aimed at non-technical users, and those are a significant slice of the OSX user population.

So yeah, I think it's worth paying for and I recommend it unreservedly. While dd may be better for some, they're not the ones asking me for backup software recommendations.

(Like Mr. Jones, I'm also not affiliated with shirt pocket in any way other than being a satisfied customer.)

What can't you do on OSX than you can on Linux?

Incremental backups

http://blog.plasticsfuture.org/2006/04/23/mac-back up-software-harmful/

Yes, I know about Time Machine, but it's not out yet, and may not be able to do remote backups and may have other limitations.

I just want to know why you would want to replace OS X with Linux?

Try to implement a decent incremental backup solution in OS X. It simply can't be done.

In Linux (or BSD) this is ridiculously easy. A simple script using rsync and cp w/ hard links does the trick. There are also software packages that make it even easier.

Once Leopard comes out, Time Machine may or may not be the answer, but I'm talking about right now.

Apple has being going gangbusters making it easier for little-shop guys to write professional apps. Look at Core Data, for example. (They're doing about everything they can, short of using a real HLL. *duck*)

And it shows: all of the top apps today, by any measure, come out of either Apple, or little places nobody's heard of. Adobe and Microsoft are really dragging their feet with Intel binaries, but they weren't really even great apps on PPC. They were mostly just "you have to have this" apps. MS Office on the Mac never felt like a real Mac app. Some of the biggest names in software are just plain bad at the Mac (Retrospect's backup apps are rated "Avoid at all cost")

Result? If I want a not-quite-Mac office suite, I can get OpenOffice -- oh, and it's Intel-native and saves me a few hundred dollars. When presented with these choices:
- buy the Windows version, and run Windows on the Mac (expensive, bad interface)
- wait 6 months for the Mac version, which won't be great, anyway (semi-expensive, ok interface)
- buy a no-name Mac app that does most of what I want now (cheaper, good interface)
- find an open-source port that does what I want (free, bad interface)
I can't imagine any Mac user picking #1.

This doesn't mean the end of the Mac. It means the end of big companies pushing out crappy software. Between Apple's productive development environment helping little guys compete with the big guys, and open-source apps and ports making people wonder why they're spending $500 for a single app, there's not much room for big software houses who make crappy software any more.

Good riddance.

I assume that these can be made to work with ZFS by making hidden files.

Using hidden files for the resource forks would also make backups WAY WAY easier and more reliable than what is available now.

I'm no expert, but I can point you to a couple of interesting web pages by people who do seem to know a lot of the details:

• Mac Backup Software Harmful and the earlier The State of Backup and Cloning Tools under Mac OS X at plasticsfuture
• MacOS X Backups at Seth's Unix Tips

You also need to think about what your backups are for and how much time and money you're prepared to expend: for some, burning a few personal files to CDR every few months will suffice, whereas for others an external HD holding a complete clone is the thing, and power users may need daily or weekly incremental backups with the ability to retrieve any file going back years.

Personally speaking, I'm in the middle category, with a large external Firewire HD holding a clone of each of my drives, which I redo every month or so. (Having it bootable is also a good idea, and has saved my bacon at least once!) I've mostly been using Carbon Copy Cloner, which has given good results, but I've recently switched to SuperDuper! which is cheap and seems to preserve absolutely everything. But don't take my word for it: read the linked pages, work out your needs, and make up your own mind.

But DO think about it! Disaster WILL strike in some form or other; disks DO fail (as I know to my cost), and you need to plan for it. It's not a question of how much time or money you can afford to spend; it's a question of how much data you can afford to lose!

I'm no expert, but I can point you to a couple of interesting web pages by people who do seem to know a lot of the details:

• Mac Backup Software Harmful and the earlier The State of Backup and Cloning Tools under Mac OS X at plasticsfuture
• MacOS X Backups at Seth's Unix Tips

You also need to think about what your backups are for and how much time and money you're prepared to expend: for some, burning a few personal files to CDR every few months will suffice, whereas for others an external HD holding a complete clone is the thing, and power users may need daily or weekly incremental backups with the ability to retrieve any file going back years.

Personally speaking, I'm in the middle category, with a large external Firewire HD holding a clone of each of my drives, which I redo every month or so. (Having it bootable is also a good idea, and has saved my bacon at least once!) I've mostly been using Carbon Copy Cloner, which has given good results, but I've recently switched to SuperDuper! which is cheap and seems to preserve absolutely everything. But don't take my word for it: read the linked pages, work out your needs, and make up your own mind.

But DO think about it! Disaster WILL strike in some form or other; disks DO fail (as I know to my cost), and you need to plan for it. It's not a question of how much time or money you can afford to spend; it's a question of how much data you can afford to lose!

As many have pointed out, standard Unix backup tools aren't good on OSX.

Surprisingly, many OSX backup tools aren't either. There's an extensive comparison of many different backup programs for OSX and it has lists of exactly what the programs will backup/restore and whether or not those things tend to be important.

Backup on Mac is not as easy as one would think...

http://blog.plasticsfuture.org/2006/03/05/the-stat e-of-backup-and-cloning-tools-under-mac-os-x/
http://blog.plasticsfuture.org/2006/04/23/mac-back up-software-harmful/

Maybe TimeMachine will offer an interesting solution...

http://www.apple.com/se/macosx/leopard/timemachine .html

Backup on Mac is not as easy as one would think...

http://blog.plasticsfuture.org/2006/03/05/the-stat e-of-backup-and-cloning-tools-under-mac-os-x/
http://blog.plasticsfuture.org/2006/04/23/mac-back up-software-harmful/

Maybe TimeMachine will offer an interesting solution...

http://www.apple.com/se/macosx/leopard/timemachine .html

There's a pretty good analysis of the various tools available here. The only tool it recommends highly is SuperDuper, which I've since switched to, and had good results with.

(There's another analysis here, which has more mixed feelings.)

In particular, SuperDuper! preserves all metadata, while CCC misses BSD flags, creation date, HFS+ extended attributes, the locked flag, and ACLs. It also knows about Spotlight. The free version works fine, but you can also pay to add scheduling, incremental backups, etc.

(Disclaimer: I've no connection other than as a user who's just moved from CCC to SD!.)