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Build your own portable external hard drive

PC Microstore - Parts list > Drive Enclosures > EXTERNAL 3.5. I just walked by cousin through partitioning an external hard drive and formatting it for use in Windows XP. Why would you want to do this, you ask? Well, you could save considerably more money if you bought the enclosure and a regular 3.5" IDE hard drive separately. Then you could build and initialize your external hard drive for use with your system. Let's review the downsides, and the benefits.

Cons:
1. More time taken up by doing it yourself.
2. If something goes wrong, who do you blame? The enclosure manufacturer or the drive's manufacturer -- hence, more time off your hands again for troubleshooting the problem.

Pros:
1. You can make sure you get the best drive for the best price.
2. You can partition the drive the way you like it.
3. Having an enclosure is a great way to clone a current hard drive without having to crack open your PC's case.
4. You can format the drive in just about any filesystem you'd like.
5. It's usually cheaper, if not, rarely more expensive than to buy from CompUSA or BestBuy a pre-built external drive.

The hardest and most time consuming part of getting the hard drive to work for my cousin was to initialize the drive -- i.e. partition and format it. It was particularly difficult because we had difficulty trying to find the replacement program for fdisk (in Windows 98 and earlier MS OS'es). Putting the drive together isn't too difficult -- the enclosure should come with instructions as to how to physically put your drive into the enclosure. Once that's done, you'll need to partition the drive and format it -- read on to find out how we did it in Win XP.

Luckily, Win XP does have a partitioning program called "Diskpart." You have to run this program at the command prompt. To get to the command prompt you do the following sequences, the commands in quotes are what you have to type at the prompt:

1. Click the Start button
2. Click the Run... option
3. Type "cmd" when prompted by the Run program. A command prompt shell should then appear.
4. In the shell, type "diskpart"
5. Now, if you haven't already done so, plug your drive into your USB port.
6. In the diskpart program, type "list disk"
7. One of the disks listed should be your external drive. To choose which drive to work on, type "select disk X" where X is the drive number assignment -- 0 is the first assignment, 1 is the next and so on and so forth.
8. Now, here is where you need some forethought and planning. If your drive is large, it will probably perform better if you partitioned the drive into multiple partitions. I am going to show you how to partition a 120GB hard drive into three almost equal partitions. There also exists different types of partitions, so I will show you my convention in partitioning a drive into 3 or more partitions. Think about how you want to partition your drive, decide and move on.
9. If you want to partition your drive into just 2 partitions, you probably could get away with creating two primary partitions. And the command to do this in diskpart is "create partition primary size=XXXXX" where XXXXX is the size of the partition in megabytes, so 40000 represents roughtly 40,000 MB or 40 GB. Do "create partition primary size=XXXXX" once and then "create partition primary" once more to partition your drive into two partitions. Notice that I didn't place a size parament on the second call since leaving it blank means that it will use whatever available space that is left on the drive.
10. However, if you want to partition the drive into 3 or more, you would have to first create a primary partition specifying the size of that primary partition and then create an extended partition of whatever is left. Then what you would have to do is create logical partitions within this extended partition. For example, three 40GB partitions in a 120GB drive would mean I would do the following in diskpart:

a. "create partition primary size=40000"
b. "create partition extended"
c. "create partition logical size=40000"
d. "create partition logical"

You always have to create an extended partition first and then logical partitions within it (with size specifications if you want) -- you cannot create logical partitions otherwise. Of course, you could probably get away with 3 primary partitions, but I wanted you to see my convention of partitioning drives. After you're done partitioning, type "exit" to get out of diskpart. Now you're ready for the next step.
11. The last part before getting to use your drive is to format the partitions. In Win XP, the partitions will need to be formatted as NTFS. Be advised though, if you format as NTFS, you cannot use it in older windows machines. If backwards compatibility is a primary concern for you, you will have to format as FAT32. In Win XP, the Disk Management tool is what you use to format partitions. Make sure your drive is plugged in again. Click the Start button --> Right click the My Computer icon --> Right click the Manage option. Under the Storage menu item, there is an item called Disk Management (choose it). This option will show you all the partitions in all available drives. Go ahead and highlight and choose the partitions that was newly created. You will need to assign drive/volume letters and then format them. It's as simple as that.
12. Once all this is done, safely remove your USB device (if attached to your USB port) remove the drive and reattach to use your new home-made (well, home initiated) external hard drive.

One of these days, if I ever have to do it and document it, I'll talk about how you could initiate a drive for use in Linux -- i.e. partitioning the external drive using Knoppix Live Linux CD and formatting it as a FAT32 partition or even reiserfs partition. And Knoppix could also be used to clone a current hard drive to the new external drive using the handy-dandy "tar" shell command (or maybe "dd" would work better). Yes, ladies and gents, Knoppix is that powerful.

Posted by johnvu at September 22, 2003 06:09 PM