InfiniteMac OSx86 - View Single Post - Disk Utility

naquaada · 04-26-2008, 03:52 AM

Make use of Disk Images (.dmg, .sparseimage)

The Mac's Disk Images are a great thing. You can use them to burn, sort and archive files. There are two main types: The standard disk image (.dmg) which uses all the space on disk you define it. Then there's the growing image (.sparseimage). This image only uses so much space on the disk which it contains. Both types have advantages and disadvantages. The .dmg image needs more space on disk, but it works more like a real drive, f.e. it can be better defragmented. A .sparseimage needs less space, but if you delete files in it the space will not be freed on the real HD. If you defragment it also will grow. But in the most cases the .sparseimage is the better choice.

How do I create a disk image? Start DIsk Utility and use 'New Image' in the toolbar or 'File/New/Empty Image' from the menu. You get a requester for the name with a lot of options at the bottom. At the top you can select the path and the file name it should have. At the bottom you can enter the name the disk image will have if you open it (can be changed later, of course). In the next field you can change the size. In the most cases select 4,7 GB DVD Image. If you want to use a disk image on a FAT32 drive (f.e. portable harddisk) enter 4095 MB as custom size. Encryption is normally unneccessary. For the partition table use always 'No partition map', i have encountered problems with other types. For the image format 'read/write disk image' will create a .dmg, 'sparse disk image' will create a .sparseimage file. If you click create, a new removable drive will appear on the right side.

For what can I use a disk image?

It helps you f.e. to clean up the harddisk. I had from former times a collection of about 100.000 MIDI files. I you have them directly on your HD, spotlight has to collect all 100.000 files - and normally are MIDIs unneccessary for Spotlight. So I put them all in an image. I have the files, they are sorted but on the real HD there are 99.999 files removed. It is good for all files with small file sizes, f.e. Amiga MOD files. It's also good for complete sets, f.e. a comic collection. I also have a image of useful Tools, installer packages, system drivers, Icons and so on. I created a sparseimage with 4095 MB for them and so I have the stuff fine sorted. If I want to install a program I havn't to search the whole HD, I only have to do look in that image. And I can open it via menu and with a hotkey, so it's very handy. And it could never be bigger than 4095 MB, so I always could be sure it fits on a FAT32 disk or an a DVD.