Using Time Machine to Restore a Full Drive: Some Questions

Question

I have a 24" iMac C2D with a 640GB drive that is 4GB away from being full. I have a Freenas NAS with another TB and two 1TB FW800 external. I have pretty much everything backed-up in one way or another, most of it a bit scatter-shot and hard to collate, so I want to reformat and reinstall OS X Snow Leopard to get a clean start and a freed-up drive.
Once of my 1TB I have dedicated to Time Machine and it's full. I get notices now and then that it's deleting some of the data to make room for more.
My question is this:
If I reformat and kill all the data on my iMac is the data fully replicated in Time Machine? Anything I should be worried about?
I don't just want to refill my Mac again, so I mostly just want all the email back and my music, but served off-drive. Are there any pitfalls I should be aware of? I plan on going over more detailed instructions (any tips on the best tutorial?) before beginning.
JoeL

Answer 1

joeldm wrote:
I have a 24" iMac C2D with a 640GB drive that is 4GB away from being full. I have a Freenas NAS with another TB and two 1TB FW800 external. I have pretty much everything backed-up in one way or another, most of it a bit scatter-shot and hard to collate, so I want to reformat and reinstall OS X Snow Leopard to get a clean start and a freed-up drive.
Not the best idea. Recovering what you want will be even more scatter-shot.
MUCH better will be to delete what you don't need, and/or archive old stuff and delete it.
Especially if you have apps you want to "leave behind," the ones you want to recover will be a problem, unless you have all the original discs and serial numbers. Apps that are installed with their own installers put other files in other places, besides the app in Applications. If you don't know what and where all those files are, the app won't work properly, if at all, without them. Worse, you may not know that until much later, when you try to use a feature you haven't tested.
Ditto all the little things, like settings and preferences, plus bookmarks, browser history, etc.
You need to do some of that +*very soon.+* Your Mac will get slower and slower as the HD nears getting full. Soon apps will begin to fail, files will begin to get corrupted, eventually it will crash and not restart.
Most folks say you should keep a minimum of 10 GB or 10% of your OSX drive free (15% or 20% is much better), depending on how you use it.
Once of my 1TB I have dedicated to Time Machine and it's full. I get notices now and then that it's deleting some of the data to make room for more.
My question is this:
If I reformat and kill all the data on my iMac is the data fully replicated in Time Machine?
All the data that's now on your iMac (and any externals that are being backed-up) will be there. Things you've deleted may not be, depending on how long they were on your system, how often it was backed-up, and how old your oldest backup is. See #12 in Time Machine - Frequently Asked Questions (or use the link in *User Tips* at the top of this forum).
But if you really want to do this, I'd strongly suggest making a separate, independent backup, probably a "bootable clone," via CarbonCopyCloner or SuperDuper. You can test it by booting up from it and using your apps to be sure everything's there and working; plus the instant you click erase on your internal HD, you no longer have backups -- you only have a single copy, and while it's rare, backup drives occasionally fail while doing a restore.
I don't just want to refill my Mac again, so I mostly just want all the email back and my music, but served off-drive.
Not sure what you mean by "served off-drive." Do you mean you want it on an external? If so, move it there first (and be sure the external is also backed-up by Time Machine).
For iTunes, see: Moving your iTunes Music folder
For iPhoto, see: Moving your iPhoto library
I don't think you can move Mail out of your home folder. Check in the Mail forum about that.