Regular readers of the blog will know that I post on technology topics occasionally, and today is one of those occasions. I like Windows Vista. (I'm not ashamed to say it, either). I especially like the ability to incrementally write to the same CD-R or DVD-R over time and across various computers (as long as they are running Vista--these same discs can be read, but not written to with XP). In any event, here is a technology column I did recently on this topic.
Windows Vista has two file systems that it can use to burn CD and DVD data disks. I'm not talking now about music CDs or video DVDs. I'm talking about data (files and folders) saved to a CD or DVD from your Windows Vista workstation.
The two new file systems, or ore correctly "formats," are called Live File System format and "Mastered" format. The default is Live File System, but it is important to know the difference. Let's walk through the steps of writing data to a CD-R (this discussion with minor variations discussed later applies to CD-RWs also).
First, insert a blank CD-R into the CD-RW or DVD-RW drive (DVD-RW drives can also write CDs, but CD-RW drives cannot write to DVDs). You will see something like the following dialog box.
I say "something like" this dialog box because its contents will vary depending on the software you have installed. If you have the Roxio, Nero, or other CD/DVD burning utilities on your system you will see choices for them. For our purposes of using Windows Vista to burn your disk, choose "Burn files to disc" as illustrated. You will see a dialog where you can enter a volume title, like this:
As indicated in the illustration above, the Live File System makes your CD almost like a floppy disk. You can add files to it over time, and from different computers, and continue to do so until you "close" it. (See below). When you "erase" a file from it, however, you do not regain the space on the disc on CD-R media. Windows Vista actually burns pits into the disk surface, writing files as you go. "Erasing" one of these files eliminates any reference to it in the file allocation structure, so that it appears to be gone from the CD, but the pits are still really there, which is why you can't re-write that part of the disc and why you cannot regain the disc space taken up by an "erased" file. The one down side to using the Live File System is that it is only readable by Windows Vista and Windows XP operating systems. It cannot be read on earlier systems, or on other devices.
After clicking "Next" from the Burn a Disc dialog, your CD-R will be formatted:
Then the Windows Explorer (Vista version) will appear and you can begin adding files to the disc. You can copy and paste them onto the CD-RW drive, as it is represented in the Windows Explorer, or drag them there, or right-click and "Send To" them there. It doesn't matter. As soon as you begin adding files to the Explorer window, the CD-RW drives begins writing them to the disc.
You can return to add more files later. If you eject the disc, Windows will tell you it is closing the session so that the disc can be used on other computers. This does not mean that you can no longer add files to the disc. As long as you use the disc on another Windows Vista computer, you can continue to add or "erase" files. If you remove the disc and take it to a Windows XP computer, however, you will be able to read the disc, but not add to it.
The drawback, if it is one, with the Live File System is that discs created with it cannot be read on non-Windows Vista or XP computers, or CD/DVD players. To make a disc that is compatible with the widest array of equipment, you should use the "Mastered" format. If you have ever created a data CD with Windows XP, you know how the Mastered format works. You select files from throughout your file system and "place" them on the disc. What actually happens is that pointers to the files get placed in a temporary work space. They are not actually written to the disc until you issue the write command. One write operation occurs, and then the disc is finalized so that it cannot be used again. Here is an illustration of files waiting to be written to disc.
Click the "Burn to disc" button (or just right-click anywhere in the window and choose "Burn to disc" to perform the write operation. When done, Windows will finalize the disc, and offer to write another:
When you create a disc using the Live File System, Windows will not offer to burn another because it writes as it goes. With the Mastered format Windows knows the disc is complete, but still retains the pointers to the files to be written in a temporary location. If you choose not to create another disc, the pointers will be erased and the disc ejected.
Which format is best? Obviously, they serve different purposes. It's nice to have the option of adding and deleting files from a CD or DVD using the Live File System, and especially useful for incremental backups. On the other hand, if you move between many computers and need to be sure you can read your data on any device, then the Mastered format is what you should use.