FAT/FAT 32 What is FAT/FAT 32? When you get a new hard drive, it will be a clean slate. It has no information on it, and won't be able to hold any information yet. Imagine having a new office with blank walls, no shelves or cabinets, nothing. In order to be able to store files in an organized manner, you first need to decide how you want to store the files, in cabinets, or on shelves, how many shelves or cabinets, what size etc. and then make that organization system available by installing shelves or cabinets. The same thing applies to a new hard drive. Before you can store information on it, you need to decide how the drive is to be organized. There are many different file systems out there because each operating system supports different ones, such as the UNIX file system, the Windows NT file system NTFS, Windows 98 FAT 32, Windows 95 and Windows 3.1 FAT 16, etc. When you get the hard drive, you first need to run a command called FDisk from a DOS prompt. If you run this utility on a hard drive that is bigger than 512MB, you will be asked whether you want to enable large disk support. That question is where you decide. If you answer Yes, FDisk will use FAT32 - if you say No, it will use FAT16. Then you need to create at least one partition on the drive, reboot, and format it. After formatting it, you can now store information on the drive. To keep track of what's on the drive, a table of contents is needed and that's where FAT comes is. FAT stands for File Allocation Table. The Math Let's do some math to understand the difference between FAT (or more exact FAT 16) and FAT 32. When you partition and format the drive, it is being organized into a lot of cubby holes, so to speak. Those are called clusters, which are numbered by the FAT to keep track of them and what's in them. FAT 16 uses a 16 bit number to number them, and the highest number you can display using 16 bits, is 2^16 = 65,536. The biggest possible size each cluster can be is 32,768 Bytes. Therefore, if you take the maximum number of clusters - 65,536 - times the maximum cluster size - 32,768 Bytes -, you get the maximum hard drive size FAT can handle - 2,147,483,648 Bytes. Bytes is a pretty ugly number, too many digits. To make it more manageable, you need to understand that computers use binary systems, which means all numbers are based on 2. Here's how you convert Bytes to Kilo Bytes to Mega Bytes etc.: 1 Kilo Byte (KB) is 1024 Bytes - 2^10 1 Mega Byte (MB) is 1024 KB - 1024 * 1024 - which is 1,048,576 Bytes - 1024 * 1024 * 1024 1 Giga Byte (GB) is 1024 MB - 1024 * 1024 * 1024 - which is 1,073,741,824 Bytes Do hard drive vendors lie? You might notice that the new hard drive that you installed, gives you less than the amount of storage space advertised. Why is that? Well, the marketing department of the vendor doesn't know too much about bits and bytes and binary system. To make it easier to calculate, they assume that 1 KB is 1000 Bytes, 1 MB is 1000 KB, etc. which of course is wrong as you just learned a minute ago. So when they have a drive that can hold 8,400,000,000 Bytes, they just call it 8.4 GB and say that's close enough for government work. Not so. To figure out the correct size of that drive, divide 8,400,000,000 Bytes by 1024 and you'll get 8,203,125 KB. Divide that by 1024, and you get 8,010 MB. Divide that by 1024 and you get 7.82 GB which is the actual size of your hard drive in GB. That's several hundred MB off from the 8.4 GB you though you would get. Anyway, back to FAT 16. We calculated that the maximum hard drive size FAT can handle is 2,147,483,648 Bytes. Using the math explained above, this turns out to be 2048 MB or 2 GB. If you try to format a drive bigger than 2 GB using FAT 16, you will never get more than 2 GB because of this limitation. As a result, you would need to partition the drive into smaller logical drives, each no bigger than 2 GB, to take advantage of its capacity. If you have a big drive, you end up with a lot of drives this way. Now FAT 32 comes into play. It uses a 32 bit number to keep track of the clusters, and the highest number you can display using 32 bits is 2^32 = 4,294,967,296. A LOT bigger than 65,536, isn't it? Therefore it can track a lot more clusters on much bigger hard drives, theoretically up to 2 Tera Bytes. This means that the limit of 2 GB per partition/drive no longer exists with FAT 32. You can now make a 10 GB hard drive one big drive instead of having to separate it into 5 2 GB partitions. Another advantage of FAT 32 is that because of its capability of tracking so many clusters, you can divide the same drive into much smaller clusters. The reason this is very useful is this: Let's say you have a 2 GB drive, formatted it using FAT 16, and end up with 65,536 clusters, each one 32 KB in size. If you store now a small text file that is only 1 KB big in that cluster, the other 31 KB of that cluster are wasted free space, since there can be only one occupant per cluster. If you store a file that is 33 KB on the drive, it will use two full clusters, one for 32 KB and one for the remaining 1 KB. Again, 31 KB are wasted. If you format that 2 GB drive using FAT 32, the clusters will be a lot smaller, 4 KB, and there will be a lot more of them. That means if you store that 1 KB text file on the drive, only 3 KB will be wasted, not 31 KB. And if you store that 33 KB file on the drive, it will use 9 clusters to store it, but the last one will only waste 3 KB, not 31. A major difference. This can be of great help when you are running low on hard drive space because it uses the drive space so much more efficiently. I have converted many drives from FAT 16 to FAT 32, and it always resulted in several hundred MB of wasted space recovered and turned into free space, usually 10-15%. OK, now that we know all that theory, let's talk about how to create a FAT 32 drive and how to convert a FAT 16 drive to FAT 32. Before we proceed and talk about creating and converting, a few things need to be mentioned: The only operating systems that support FAT 32 are Windows 2000, Windows 98 and Windows 95 b. To see what version of Windows you have, go to Start/Settings/Control Panel/System, and look at the System description. If it does not say Windows 2000, Windows 98 or Windows 95 4.00.950B or 950C, then do not use any of the procedures listed below. You will lose all information on a FAT 16 hard drive when trying to convert it to FAT 32 in an operating system that does not support it. If you have a dual-boot system, e.g. Windows 98 with NT 4, Linux, etc., the other operating system will not be able to read any information of a drive that uses FAT 32 because NT 4, or UNIX do not understand FAT 32. If you use a compression utility to get more space out of your drive, do not use FAT 32. If you ever need to go back to FAT 16, e.g. you decided to make a dual boot, or install NT 4 on the drive instead, you cannot do this with Windows. Once FAT 32, always FAT 32. The only way to convert back to FAT 16 is with a third-party utility called Partition Magic from Power Quest at http://www.powerquest.com. If you decide to convert an existing drive to FAT 32, don't do it unless you have all the information from the drive backed up. Changing the FAT is a major operation and if something goes haywire, the table of contents for your drive can get destroyed. If you decide to convert an existing drive to FAT 32, it is a good idea to run Scandisk and Defrag first to make sure the drive is healthy. Creating a FAT 32 drive If you have a new or blank hard drive with nothing on it, then it is very easy to create a FAT 32 drive. First, you need a boot disk that was created with either Windows 95B or higher, or with Windows 98. To learn how to create a boot disk with CD-ROM support, go to http://www.pcnineoneone.com/howto/cdboot1.html. Boot with the floppy. At the A:\ prompt, type FDisk. You will be asked whether you want to enable large disk support. Answer Yes to enable FAT 32. Now use the FDisk menu to create your partitions as desired, reboot and format the drive(s) as normal. Then install the operating system. To confirm that the drive is indeed FAT 32, in Windows, open Windows Explorer, right-click the drive, select Properties and look at the File System line. If it reads FAT, it means the drive uses FAT 16. If it reads FAT 32, it uses FAT 32. Converting a FAT 16 drive to FAT 32 After reading about all these great advantages of FAT 32, you probably are eager to check whether you are already using FAT 32 and it not, how to convert. First, check to make sure that you have the right version of Windows. Go to Start/Settings/Control Panel/System, and look at the System description. If it does not say Windows 2000, Windows 98 or Windows 95 4.00.950B or 950C, then do not think about converting because your Windows version is too old. But if you have the right version of Windows, check if you already have FAT 32. Open Windows Explorer, right-click the drive, select Properties and look at the File System line. If it reads FAT, it means the drive uses FAT 16. If it reads FAT 32, it uses FAT 32 and there is no need to convert. If you use Windows 95 B To convert a drive under Windows 95 B, you need a utility that does the job for you since Windows 95 B does not come with a conversion utility. This is a tiny little program that was made by Microsoft but never publicly advertised. Download the Windows 95 B FAT 32 conversion utility at http://www.pcnineoneone.com/dloads/cvt.exe Converting the drive is pretty easy. Just boot to DOS by rebooting, then pushing the F8 function key when you see the words Starting Windows 95. Select Command Prompt Only from the menu. Once at the DOS prompt, run the cvt.exe program. It looks a lot like the DOS version of Scandisk. Once it's done, just reboot. To confirm that the drive is indeed FAT 32, in Windows, open Windows Explorer, right-click the drive, select Properties and look at the File System line. It should read FAT 32. If you use Windows 98 Windows 98 comes with a built-in FAT 32 drive converter. You should find it under Start/Programs/Accessories/System Tools. If it's not there, then you can install it by going to Start/Settings/Control Panel/Add Remove Programs/Windows Setup, highlight System Tools and push Details, check the box for Drive Converter FAT 32, insert your Windows 98 CD-ROM and click OK to install it. Now you go to Start/Programs/Accessories/System Tools and start the Drive Converter. It is a convenient wizard that will walk you through the process. Combining Partitions If you have multiple 2 GB partitions and convert them all to FAT 32, they will still be separate partitions, even though FAT 32 supports bigger partition sizes. The straight-forward way to make it one big FAT 32 drive would be to back up all your data, use FDisk to repartition it using FAT 32, format the drive, then reinstall Windows, your programs, and restore your backed up data. This is quite a project, but it gives you a chance to clean house which you should do every once in a while anyway. If you don't want to go through that trouble, you need to get a third-party utility such as Partition Magic from Power Quest at http://www.powerquest.com. After installing it, you need to resize the partition you want to eliminate down to where it's just big enough to hold the data already on it. Then add that new free drive space to the partition you want to keep. Now copy the data from the partition to be eliminated to the partition to be kept. Delete the empty partition and add the free drive space to the partition to be kept. You need to repeat this procedure for all partitions you wish to eliminate. http://www.pcnineoneone.com