PDA

View Full Version : archiving a system snapshot


camner
12-29-2008, 04:46 PM
I once learned the lesson of multiple backups when I accidently hosed both my main drive and my principal SD! backup drive (my idiocy...neither an SD! problem nor a hardware problem).

I'd like to be able to keep multiple archives of past backups. The problem is that as my data grows in size (principally images) so that my main drive now occupies nearly 250GB, keeping multiple 250GB backups takes lots of room.

So, I've been thinking about strategies for this, and I've come up with two:

1. Create a Sandbox with "shared users" only. If I understand what that will do, that will serve to back up everything on the drive other than the "users" folder. This can serve as a "system snapshot," and I can keep as many of these as I wish.

The only concern/question I have about this is how to restore. I THINK I should be able to restore this kind of snapshot to a Sandbox, but not to an underlying drive (or maybe I can, using the technique of "cloning back a Sandbox to a main drive").

Perhaps the best way to implement this strategy would be to make my Sandbox a "shared users" only sandbox, and then periodically make an "all files" backup of the Sandbox as a "system archive."

Will this work?

2. Take my Documents folder (or some of the subfolders) and move them off to a separate volume, then create aliases on my main drive. Then take a snapshot by cloning the entire drive (which will clone the aliases without resolving them). Restoring would mean simply cloning back.

I'm not sure I think it is a good idea to alias the Documents folder, as the system expects that to exists, I think.

My preference would be method 1, if it would work.

Thanks for your help...if I take this approach, I want to make sure I have a workflow that will work.

dnanian
12-29-2008, 04:55 PM
You can certainly do a Sandbox for this, and keep more than one, and restore by cloning back the way we've previously discussed (and is in the User's Guide).

camner
12-31-2008, 05:34 PM
Thanks for your reply.

As I'm thinking through this strategy, I'm wondering about the relative advantages/disadvantages of making a "shared users" Sandbox vs. a "shared users and Applications" Sandbox. I can think of a few considerations:

1. With a "shared users and apps" Sandbox the Sandbox takes up less room (but storage is cheap...I don't care about this) Advantage: "shared users and apps"
2. With a "shared users" Sandbox, I end up with two full copies of everything in the Applications folder. This means that when I do an "open with" selection I get two copies of every entry, and if I ever (and I do) use the "Use this application to open all documents like this" I may well end up accidently choosing the wrong version of the application, because "open with" doesn't disclose which volume their choices reside on, at least not as far as I can tell. Advantage: "shared users"
3. With a "shared users" Sandbox, I don't have to worry about making sure that newly installed apps get reinstalled on the underlying drive, either manually or by "cloning back." Advantage: "Shared users"

Are there other pros and cons of a "shared users" vs. "shared users and apps" Sandbox?

dnanian
12-31-2008, 06:00 PM
With a full backup, rather than this, you don't have to worry about it, and can archive-and-install to go back to a different system. I'm just not sure archiving a bunch of these system snapshots is necessary.

camner
12-31-2008, 06:12 PM
Maybe this is overkill, but I'm trying to provide some protection against having my backup drive getting hosed. I make a regular SD! backup to an external drive, backing up my entire drive (not the Sandbox). But, I had an experience once that when I needed to go to the backup, the drive wouldn't work, so there I was, with neither a working drive nor a working backup.

I have data backup redundancy by using Time Machine (to another drive...not the same one I back up to using SD!). I wanted to create some redundancy for my system and my apps as well, and keeping several 220GB whole drive backups takes a lot of room! So, I thought I could make smaller (around 40GB) "snapshots" of the system and apps by making a copy of my sandbox (assuming it's "shared users" only).

If there is a better strategy, I'm certainly all ears!

dnanian
12-31-2008, 06:33 PM
I think the way to do that is to make a second full backup (as I suggest in the Introduction to the User's Guide)...