Using external HDD for Time Machine and files in one single partition ?

Question

Hello everybody.
I've been searching for some time now and have encountered some contradictory answers, so I turn to you.
I would like to know if it's possible (one) and safe (two) to use a single partition for both Time Machine and file storage. I've read that this should be ok, since TM is actually only a single folder, which means the rest can easily be used as a standard Finder drive. Some people say however that this is not good to do so, because TM will run out of space quicker. But if the -let's say- 30Gb used for files where used by TM after a month, that would be the same, wouldn't it ? It would simply erase older backups. But is it safe to do so ? Will Time Machine not makes errors when accessing files or doing an entire system backup ? I don't won't to make a new partition really, that's why I'm asking you here, to let me know some arguments about it.
Thank you very much for your answers.

Answer 1

Marekova wrote:
Yet, overlooking that, you say "safe: mostly", why is that ? where's the "danger" or, what where you thinking when you said that ? Aren't these simple folder's ? Do you mean that, because during a full backup, these "stranger" files could be a problem ? It would be great if that was clarified, since I've found no indication about it elsewhere, has anyone tryed it ?
Oh, yes folks have tried it. That's why I (and many others) recommended against it.
Here's a similar thread from just the other day: http://discussions.apple.com/thread.jspa?threadID=1926893 Note the responses from the top 2 "gurus" on this forum.
I probably should have asked you what you mean by "safe." If you mean, will TM delete other files on it's partition, no, it won't. If you mean, can there be problems, then yes, there can be conflicts and difficulties, as mentioned.
As to whether TM backups are simple folders, no, they aren't. They look like normal files and folders, but they actually contain what are variously called "hard links," "multi-links," and (my own personal favorite term) "ghost clones." Think of them as very fancy aliases. So they're not to be fooled with directly, by us mere mortals.
If you want more on this: http://arstechnica.com/apple/reviews/2007/10/mac-os-x-10-5.ars/14
and/or: http://www.appleinsider.com/articles/07/10/12/roadto_mac_os_x_leopard_timemachine.html
and, if you haven't seen it yet: http://www.apple.com/findouthow/mac/#tutorial=leopardtimemachine
You should also know that, for some reason, TM stores it's backups differently when it does them wirelessly. In that case, they're in a "SparseBundle," very different from the structure used for directly-attached backups.
All the more reason to put each Mac's backups in a separate partition, and if you want to store other data there also, a 3rd partition for that.
I've been using Mac since many years now, but I have no idea about backups, so excuse me if the statements appear a little childish.
Nope. Even those of us who are "older than dirt" and have used many flavors and varieties of backup systems for decades are in a whole new world with Time Machine.
And most of the folks on this forum who found themselves in deep trouble got there because they assumed things or didn't ask.