View Single Post
Old 04-02-2004, 05:19 PM
dnanian's Avatar
dnanian dnanian is offline
Join Date: Apr 2001
Location: Weston, MA
Posts: 14,838
Send a message via AIM to dnanian
Originally Posted by camner
2. I haven't tried this yet, but working with other backup utilities (SilverKeeper, for example), it takes a while to actually do the smart backup, so I set it to only copy changes to my Documents folder. I now understand that the way SD works, this would be a mistake!
Indeed: it doesn't take much time to evaluate the whole drive, and it would, indeed, be a mistake.

Originally Posted by camner
3. You write, on page 16 "...restoring one of these images is much, much, faster than doing a 'file by file' copy". Once again, I inferred something you didn't really say. I concluded that by creating multiple dmg images, I would accomplish two things: (1) multiple "checkpoints", and (2) quick restores (as opposed to "cloning back" from my backup drive). It still isn't clear to me what you would recommend as a backup strategy for someone who has a second internal drive whose sole purpose is backup...should I also keep periodic dmg images, or be content with regular smart updates to the 2nd internal drive.
It all really depends what you want to do the backups for, and whether you want multiple versions saved. For most people, that's overkill, so I'd recommend running from a Safety Clone, and keeping a full, smart-updated backup of the source drive (which contains the user files: there's no real reason to back up the Sandbox).

If you want to have multiple rollback points, I'd probably recommend creating a few DMG images on a drive large enough to hold them. Each should be a growable sparseimage, named -- for example -- Monday, Wednesday and Friday.

To update Monday's, you'd mount it on Monday and Smart Update to it. Same for Wednesday. This'd give you three rollback points, but note that none of them would be bootable (though restores from them should be).

Originally Posted by camner
5. Here I think you are not being clear enough in the docs. Until I read your reply, I did not fully understand the implications of doing a Smart Update with a 'cut down' list of files. The implications are sufficiently staggering (destruction of clone!) that I might suggest that when someone attempts to do so (assuming you can detect it), a nice window saying something to the effect of "hey, are you absolutely sure you want to do this--you will lose all files on the target that are not contained in the folders you specified" would be a great feature.
Well, I'm not sure how much more I can say. I point out the issue on page 10:
Do not use Smart Update to selectively copy files to or from a clone: you’ll end up with the same result as if you had selected Erase, then copy, which probably isn’t what you want. For more information, see the discussion of Smart Update on page 14.
and then again on page 14:
Important Note
As we said above, the result of a Smart Update will be exactly what you’d get if you chose Erase Sandbox, then copy files from Macintosh HD. That means that any files “outside” the set of files selected by the copy script will be erased.
For example, let’s say you did an initial copy using Backup – all files. Then, later, you decided to try to only “update” your user files the Backup – user files script.
Remember that the result of a Smart Update will be exactly what you’d get if you chose Erase Sandbox, then copy files from Macintosh HD with the same script. That means that all files on Sandbox other than the ones selected by Backup – user files will be deleted!
Instead, you should choose the same script you used previously: Backup – all files. SuperDuper will automatically skip any files that didn’t change, so you’ll end up copying the smallest amount of data possible to make Sandbox match Macintosh HD again.
Where else would you like to see a similar warning? It's hard to put it in the UI, because the fact is that people don't read warnings... unfortunate, but true.

Originally Posted by camner
Another question...can one schedule a SD cloning as a cron job?
Not at present, no.
--Dave Nanian
Reply With Quote