9:30 am

MacMost Now 57: Archiving Large Drives

Gary Rosenzweig shows you how to use Disk Utility to create a sparse image and archive large amounts of data on to it. This is useful for backing up entire Macs.

Video Transcript (Click to Expand)
If you have ever had to decommission an old Mac, perhaps to give it away or maybe sell it, you probably want to make an archive of everything that is on the drive. You never know what you might need that's on there. Let's take a look at how to do that on this episode of MacMost Now. Okay so archiving an entire hard drive can be tricky, especially if you've got a ton of stuff on it like maybe one hundred gigs or more. You can't fit that on a DVD, so what you need to do is get an external hard drive. First let's look at what you should be backing up and then let's look at how to do it. Okay, so let's take a look at what you should be backing up. Here we've got your hard drive and you should have at least four folders at the main level; applications, library, systems, and users. Inside users, you should have all the users on that machine, your main user and any extra ones you've got, also a shared folder. Now you can look inside there and see that you've got a documents folder and you think well, if I back up my documents folder I should have everything. Well, that's not the case; you've also got movies, music, pictures folders and anything that's on your desktop. So, you probably want to back up the entire user folder. Now, at the main level, you probably want to also back up your library folder. One of the most important things in your library folder that most people forget are the fonts. Now if you are a graphic designer or some sort of graphic artist you probably use all sorts of different fonts and some may end up in here. So having a back up of that is very handy. There is also a lot of other stuff in here and usually it's not very big so you want to back up the library folder. Applications is also useful, because you may have some shareware, freeware that you downloaded that is may be hard for you to get new copies of. So, back that entire thing up. Your systems folder is kind of optional though, because you should be able to recreate that by simply reinstalling leopard on any new machine. Okay, so now the program we are going to use to back everything up is called disk utility and it's in your applications utilities folder. Now inside this utilities you will be able to see on your left all your drives. So, here is your main drive and it is one partition, your Macintosh hard drive, that's where all your stuff is. And then here is an external drive I've hooked up and there's one partition on that, called MacMost Video in this case. Now, you could just start copying files from one to the other, but I found a much better way to do this is to create a disk image. A disk image is like a virtual hard drive, as a file on a hard drive. So, you can create this one file and you open it up and it is like having another hard drive on there. The great thing is when you are not using it, it just sits there as one single file and it's not taking thousands and thousands of files and showing them to you. So, to create that you go to disk utilities file menu and you can go and say new and blank disk image. You can also quickly create a disk image from a folder or from an entire disk. But, the best way to do this, I've learned, is to create a blank disk image. Once you do this, you'll have a lot of different options. These options are, basically to; give it a name, so you create it as the back up. You say where you want to save it, so I am going to save it to this external drive. You also get a volume name so when you mount this sort of virtual drive it has a name; I am going to use the same name here. Now, there's a lot of different sizes that match a lot of different things like, CD ROMs, DVDs. What we want to do is create a custom one. And you want to make sure this is bigger than all the files that you need to save. So, let's say if you are going to back up 150 gigs worth of stuff, create a 200 gig drive. And don't worry this is not going to take up 200 gigs of space. What we are going to do here is we are going to go ahead and change the image format from a regular disk image to a sparse disk image. What a sparse disk image is is it's an image that will grow in size with what is on it. So it is going to have 200 gigs on it, but will only take up lets say 100 megs say if all you have on the disk are 100 megs worth of stuff. Then we are going to go ahead and create that. Now, we will go ahead and create this file on there and then we can mount it and start moving files to it. Okay, now that we have created this drive, we see it appear here on the left in disk utility. We also see that if we go ahead and open up a finder window, we will see it appear hear as a regular drive and it is empty. Now we can just simply start dragging stuff from one finder window to another. So, we will go ahead to our Macintosh hard drive, say we want to drag all of users over to this and we can just add it to it. And then the file it's self, if we go ahead and look on MacMost Video drive, we can see it shows it there as backup.sparseimage. And we get info on it we can see that it is actually only 99 megabytes even though it is set for many gigabytes. And it will grow in size as we add things to it. And that way we keep adding things to until we have backed up everything we want. So, say we take our users folder, and the libraries folder, and the applications folder, move them all there. Now we have a complete back up inside of a single file. Now you've got a back up of everything that was on that drive and it is there as one file on an external hard drive. Now you can go ahead and give away or sell that Mac not worrying about losing any of your data. Until next time, this is Gary Rosenzweig with MacMost Now.

Comments: 2 Responses to “MacMost Now 57: Archiving Large Drives”

    10/23/08 @ 1:32 pm

    Hi Gary,

    I have recently switched to mac and started to watch your podcast which is very useful. Thank you for your efforts. I have a question about this episode though.
    Why should you create a virtual drive? Can’t you create a new folder on the hard disk and put all the files to be backed up in that folder? What is the benefit of the virtual drive?


    10/23/08 @ 1:43 pm

    Satish: One benefit is that the virtual drive is seen as a single file, instead of a folder full of files that can contain hundreds or thousands. So when the virtual disk image in not mounted, it is just a single item. That helps with organization, and with drive speed.

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