[Simon]

So recently I was looking at the partition TM is backing up to. It seems that within a second-level directory named after the Mac it's backing up, there's a 'current' symlink which points to what is basically a clone of my boot partition. Now obviously this is not really a true clone, since there's some hard link magic going on, but it still got me wondering. What if I were to make symlinks on the root level of the backup partition that point to stuff in current and then bless the partition. Would that make my TM backup a bootable pseudo clone?

Here's an example of what I'm thinking of:
[codex]/Volumes/TM/Applications -> /Volumes/TM/Backups.backupdb/myMac/current/Applications
/Volumes/TM/Desktop\ DB -> /Volumes/TM/Backups.backupdb/myMac/current/Desktop\ DB
/Volumes/TM/Desktop\ DF -> /Volumes/TM/Backups.backupdb/myMac/current/Desktop\ DF
/Volumes/TM/Developer -> /Volumes/TM/Backups.backupdb/myMac/current/Developer
/Volumes/TM/Library -> /Volumes/TM/Backups.backupdb/myMac/current/Library
...
/Volumes/TM/etc -> /Volumes/TM/Backups.backupdb/myMac/current/etc
/Volumes/TM/home -> /Volumes/TM/Backups.backupdb/myMac/current/home
/Volumes/TM/mach.sym -> /Volumes/TM/Backups.backupdb/myMac/current/mach.sym
/Volumes/TM/mach_kernel -> /Volumes/TM/Backups.backupdb/myMac/current/mach_kernel
/Volumes/TM/mach_kernel.ctfsys -> /Volumes/TM/Backups.backupdb/myMac/current/mach_kernel.ctfsys
...
/Volumes/TM/var -> /Volumes/TM/Backups.backupdb/myMac/current/var[/codex]

And if that will work, is there any developer here who would like to make a nice little utility with a decent OS X GUI for it? I'd prefer that over the quick and dirty shell script I'd have to otherwise write.

[TETENAL]

Why?

Time Machine backups are read only, so they aren't bootable no matter what. It would really mess up the backup if they could be modified.

[Simon]

And what about making it readable first? Would it then work?

[Person Man]

Originally Posted by Simon 

And what about making it readable first? Would it then work?

Probably not. I'm not sure I'd want to mess around with the Time Machine Backup like that. Apple provides a way to restore from the Time Machine backup from the installer DVD. There is no need to have a bootable Time Machine backup.

[Simon]

Originally Posted by Person Man 

Probably not. I'm not sure I'd want to mess around with the Time Machine Backup like that. Apple provides a way to restore from the Time Machine backup from the installer DVD. There is no need to have a bootable Time Machine backup.

I know that I can use MA to copy back from a TM backup. But that's not the point of this thread. I am wondering if it is technically possible to make a bootable partition using the TM current directory. And if so, what is required?

[Person Man]

Originally Posted by Simon 

I know that I can use MA to copy back from a TM backup. But that's not the point of this thread. I am wondering if it is technically possible to make a bootable partition using the TM current directory. And if so, what is required?

I'm not talking about Migration Assistant. There is a utility on the DVD that can do a wholesale restore of your drive from the TM backup.

[Simon]

Originally Posted by Person Man 

I'm not talking about Migration Assistant. There is a utility on the DVD that can do a wholesale restore of your drive from the TM backup.

That's fine too. But the question remains: can it be done with a simple shell script that creates the right symlinks, makes it writable and blesses it?

[Person Man]

Originally Posted by Simon 

That's fine too. But the question remains: can it be done with a simple shell script that creates the right symlinks, makes it writable and blesses it?

Don't know. But I think it might be likely to mess things up as far as either continuing to make backups or restoring from them.

You could try it. Other than seeing if it can be done and whether it messes up proper functioning of TM or not, what would be the value of doing this if you can completely restore your system using the startup DVD? (Other than having a bootable backup to use when the DVD is not around).

[Simon]

Again, I don't care about the value. I want to know if it can be done and what is required.

[Person Man]

Originally Posted by Simon 

Again, I don't care about the value. I want to know if it can be done and what is required.

Can't answer that. Why not try your idea? Don't use your main TM backup though. I'd use a separate hard drive with a fresh backup to mess around in.

Trial and error. You're likely to be the first person interested in such a thing. And in the absence of detailed documentation from Apple about the innards of Time Machine, trial and error is how anyone else is going to learn it as well.

Sorry I can't help much beyond that. My current experimentation is with the nitty-gritty of code signing and its impact on end user localization of Apple's System Software for languages that aren't part of a default install and for which the Apple representative in those countries either provides no localization, or (in the case of Greece, an extremely crappy localization).

Don't forget to report back to us about your findings. I'll be reporting on mine in due time.