C-Command Software Forum

Download Multipart Package

I created an install package for my product using Mac PackageMaker. I then dropped the package onto DropDMG with the following preferences set:

  • Limit segments to at most 200 MB
  • Auto open image window after mounting
  • Internet enabled.

DropDMG created 3 files:
[package name].pkg.dmg
[package name].pkg.002.dmgpart
[package name].pkg.003.dmgpart

Since I work mainly on a PC, I transferred these files to a PC, uploaded them to my website using CuteFTP, and created links to the 3 files. When I try to download the first file to my Mac (OS X 10.4.9), Safari Download Manager reports “Mounting Failed”. When I click on the links for the other 2 files, I get a screen full of garbage.

What’s wrong with the download?

Probably nothing. In order for the mounting to succeed, you need to have downloaded all three parts into the same folder. Make sure you download the second two parts as files (i.e. save them to disk) rather than single-clicking them so that you browser tries to display them. If you add this line:

AddType application/octet-stream .dmgpart

to your server’s .htaccess file, you may be able to convince your browser not to try to view the files.

OK, using that statement in an .htaccess file got me around the garbage screen displays. However, I still get the “Mounting Failed” messages when I download each of the 3 files. After I download all 3 files and click on [package name].pkg.dmg I see a single package, and the install works.

Is there any way to avoid getting the “Mounting Failed” messages? I’m sure that’s going to generate a lot of help desk work.

If you Option-click the file to download it (or use the contextual menu to save it to disk), the browser will simply save it rather than try to open (mount) it. Another option would be to use DropDMG’s encoding feature to, say, encode each piece as a .gz file. Then the browser will automatically not try to open the pieces. The downside to this approach is that you’d need an extra step after the download of double-clicking each .gz file to expand it back into a .dmg or .dmgpart.

I added a note in the Read Me file telling users they could ignore the warning. I guess I’ll see how many people read the Read Me file.

Thanks for your help.