Monday, June 29, 2009

Overburning in Mac OS X

The Mac OS X Finder and the Disk Utility (used to burn CDs/DVDs) together impose a limit on the amount of stuff that can be burned onto a CD to the specified size of the CD. And there is no way to get around this using these two.

On Windows, there exists disk burning software (a.k.a. Nero Burning ROM :) ) which supports something called as overburning, which will let you burn slightly more data than the specified capacity on a CD. Wikipedia has this to say about it. Obviously, the CD/DVD drive has to support it, but most modern drives do.

However, for Mac users, there is one simple way of overburning a disc using native (that came with the Mac) software. It’s a command-line utility called hdiutil.

Just requires three simple steps:

  1. If you don’t already have an ISO image to burn, create it by using this command in Terminal:
      hdiutil makehybrid –o image.iso files_to_burn/
    where files_to_burn is a folder which contains the file/s you wish to burn.
  2. Load an empty CD/DVD in the CD/DVD writer of the Mac.
  3. Now that you have the image, in Terminal, go to the folder containing the image and use the command
       hdiutil burn image.iso

It is very important to load the CD/DVD before you fire the burn command, because if you fire the burn command before you insert the disk, somehow hdiutil doesn’t overburn.

A word of caution, the amount of data beyond the specified capacity that you can overburn on a CD/DVD depends on the burning drive, the CD/DVD and the burning software (hdiutil here). So, be careful to remain within about 3-5% of the capacity of the disk over the capacity.


More info about the utility hdiutil can be found in Apple’s man pages here.

Wednesday, June 24, 2009

Windows cannot install required files. Error code: 0x80070017

Something that could go wrong while installing Windows 7. The backup, partitioning and other pre-requisites complete just fine. But when the installation begins to extract files and data from the DVD, you get a big error which says:

Windows cannot install required files. The file may be corrupt or missing. Make sure all files required for installation are available, and restart the installation. Error code: 0x80070017

More often than not, the simple reason behind this error is just that the DVD burning caused some little problem somewhere and corrupted a file.

There’s no quick solution, just re-burn the Windows 7 RC on a new DVD with as low a speed as you can stand. 2x or 4x should be OK. Some people are also saying that the DVD- format works more times than DVD+, but I think just lowering the burn speed should do the trick.

Tuesday, June 23, 2009

Startup disk cannot be partitioned or restored to a single partition

Software sometimes behaves stupidly and in the most unlikely of places. Here is one such – when you start the Boot Camp Assistant in Mac OS X Leopard to install Windows, in stead of proceeding from the first – informative - screen, it throws an error:

The startup disk cannot be partitioned or restored to a single partition. The startup disk must be formatted as a single Mac OS Extended (Journaled) volume or already partitioned by Boot Camp Assistant for installing Windows.

This, when you have a brand new Mac with a single clean partition.

The problem is that the Boot Camp Assistant, for some reason, is thinking that you have more than one partition of your startup disk - the disk from which Mac OS is starting up, and Windows is intended to. More than one OS X partitions, that is.

The solution is quite simple and quick really (except for the backup step):

  1. First of all, backup all of your existing data. A Time Machine backup is advisable. You should do this any time you want to play with the partitions on your hard drives – even with the correct tools at hand.
  2. Add a new partition using the Disk Utility as perfectly described here. Close the Disk Utility.
  3. Now, remove this newly created partition, again, as given here.
  4. After this, the graphic of the hard disk will again show up as one full partition.

That’s it, really. Boot Camp Assistant won’t show the same error again.

Although the problem is less baffling when you already have multiple partitions created, the solution is still to remove all partitions other than the startup one to enable Boot Camp to proceed without errors.

Just a word of caution. Boot Camp does not understand a partition created before its invocation, even if you created it expressly for installing Windows. So it’s best to let it do it on its own.