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garybollocks 10-23-2006 10:27 AM

Undersized disk image and a Boot Camp-related backup question
Having just got my hands on a brand new MacBook Pro, I'm looking into installing Windows XP through the magic of Boot Camp. So far, I've done all the sensible things, like backing up all the data on my current, 100GB drive (just over 40GB of data) to an encrypted sparse disk image, created with Disk Utility. The backup itself was done (twice) with SuperDuper!, with which I am extremely pleased.

However, I have a few questions, since I am potentially about to kill my Mac's hard disk in the face and would like to be certain that I'm going to retrieve so many hours of installation:

1) Is creating the sparse disk image (encrypted or otherwise) with disk utility, then backing up with SuperDuper!, any better than having SuperDuper! create the disk image? I'm under the impression I can't create an encrypted disk image with SuperDuper!

2) The sizes of the original hard disk and the sparse image don't match: the original is bigger at 41.1GB, while the disk image comes in at 38.8GB (mounting it and using Get Info says 38.77GB used). 2.5GB is a lot of data. It looks like the main difference is the /private/var/vm directory: 2.67GB on the Mac HD, but non-existent on the image. Looking at the scripts for the Smart Backup shows that this file is skipped over, and it looks like I've just answered my own question...

I've also seen a lot of questions about backing up a Windows partition created by Boot Camp. This is something I'd also like to do: have a backup of the FAT32 Windows partition, but using a utility that's as downright spiffy, easy to use and secure as SuperDuper!. I've been musing on this a bit and would like some recommendations....

What I intend to do is create a 32GB FAT32 partition and stick Windows XP on it. What I'd then like to do is have a backup of this volume in the same way as I've backed up my Mac HD. As I mentioned above, the Mac HD is cloned to a sparse disk image which currently resides on an external firewire drive (a 500GB LaCie disk). I want to do the same with the Windows partition: open up a sparse image under Mac OS X, copy all the Windows data to that image, unmount the image and compact it using the "hdiutil compact" command.

Of course, I can't use SuperDuper! for this (am I'm not asking for this either...well, not yet anyway...). However, before I discovered SuperDuper! I was essentially carrying out the same operation using rsync (actually RsyncX or Psync - I forget which) using a very simple shell script and the available command line utilities. The question is:

3) Can I do this for a Windows partition?

There is scant information on the web about using rsync to backup a Windows FAT32 volume, but a fair bit of it seems to say "this won't work" in one way or another. I can't yet understand why: rsync (at least the standard UNIX version) seems to struggle with HFS+ metadata, none of which comes in to play for a grand old FAT32 disk.

Since all my backup disks are HFS+, I have to do this under Mac OS X, and I'm too stubborn to shell out for another external disk just for Windows and a corresponding backup utility. Any help would be greatly appreciated, since I'm currently flying blind. Otherwise I shall try it anyway, fall at the first hurdle and sit weeping uncontrollably in front of my once shiny new laptop...


dnanian 10-23-2006 10:51 AM

OK -- creating the sparse image outside SD! is just fine (and is the recommended way if you want to use encryption). No trouble there.

And yes, you've answered your own question. We also skip temporary files, and some caches.

As far as backing up boot camp, I actually suggest using Parallels instead. It's a great option, works really well, and the file data is stored in a virtual disk file right on your HFS+ partition...

garybollocks 10-23-2006 12:46 PM

Ah, that's good news about the backup. The Windows installation has already started, so there's no turning back now.

I was considering Parallels, but the key problems are that:

a) I have to create a separate disk image, rather than using the partition that was created by Boot Camp, meaning that I'd have a number of Windows installations. This isn't a problem on its own, since I could just use Parallels without a separate Boot Camp installation, but...

b) I need access to the Firewire connection under Windows. I'm going to be running a high-speed camera for an experiment I'm working on, which connects via Firewire. The Data Acquisition software is Windows only, hence the Windows installation. Since Parallels can't access peripherals, it isn't an option for me.

So I have to find a way of backing up the Windows partition to a Mac disk using a Mac OS X backup solution.

Incidentally, the Windows installation went like a charm. Now to wait for the inevitable deluge of viruses and malware rendering the whole thing useless...


dnanian 10-23-2006 01:07 PM

I don't quite understand the (a) issue here, actually.

(b) is definitely an issue. While you can certainly access USB devices, FireWire won't work.

Good luck with this!

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