[fred]

What bothered me about booting and using the sandbox as a boot drive is that the drive would be running all day maybe for at least 12 hours a day! Wouldn't that be bad for an external drive. I'm not sure what they are designed to withstand before they fail.

I gathered from reading the documentation that if the sandbox was just used to be a backup drive then it says in the documentation that it is takes longer to track down the problem and restore everything, whereas with the sandbox as the boot disk you can be back up in minutes by just going back to the hd.

So does that mean if there was an install that buggered the sandbox, one would finish working on the hd and then restore the sandbox via the hd at a more convenient time, to how it was before the bad update and wait for a new good update?

I wasn't clear about the reverse update but now I can see how it works. So the question for me is, is it worth running from my external hd all day long. I work from home which is why I have my computer running for so many hours a day. To answer this I need to know how difficult is it to fix everything if I use the sandbox purely as a back up. For example say the sandbox has been smart updated from my hd and is identical, then I download a piece of user installed softeware and it wreaks havok. Couldn't I then just use the sandbox backup to do a smart update to restore my hd? I don't understand yet what is wrong with this, apart from having to wait for the smart update to update, which wouldn't take more than a half an hour?

Am I missing something here, is it just a matter of being able to get back to work withing a couple of minutes against half an hour? or is there more to it. Because if it's only about a half an hours wait in the unlikely event of something bad happening then it doesn't seem worth it to run the external drive into the ground.