Technology

Uninstalling U3 from Flash Drives

Recently I purchased a 2GB SanDisk U3 Flash Drive. It was on sale and I honestly have never owned a USB flash drive. I’ve always used either a network connection or CD-Rs to transport data. With the prices dropping on flash drives so dramatically, I though it might as well be time to purchase one. However when I plugged it into my computer I was surprised to find this wasn’t an ordinary flash drive.

The USB controller showed two drives when you plugged the stick in, one being a CD-Rom drive. It had an autorun that would install proprietary software for running mini-applications straight from the flash drive as well as encrypting the data on it. It seems like a neat idea in concept, except that I didn’t purchase a crappy application on a stick. I purchased a flash drive. It showed this useless CD-rom drive in MacOS and Linux, and in windows it required the user to be logged in as administrator in order to even gain access to the flash drive, making it completely useless on public PCs such as in libraries.

After doing some research I found a forum topic which discussed the issue at length. After several complaints, U3 publicly released a U3 removal tool to flash the firmware on these devices so that they are once again, simple and easy to use plain old flash drives.

Assignment Updates

I’ve finally gotten around to updating the assignments page with last semester’s work as well as several of my undergraduate class work. It’s not entirely up to date, but it’s on its way there. The projects and web portfolio should be up shortly as well.

RAID 5 Rebuild

At one time my personal files were split between several hard drives. As most nerds do, as I needed more space I added extra drives. The cost of this method is the inevitable drive failure leaving oneself with the loss of irrecoverable precious media. Hard drives are physically unreliable and so over a year ago, I decided to build a RAID 5 array.

The most economical solution at the time utilized six 320GB drives. The total total space with redundancy factored in was approximately 1.5 TB. Using the software RAID support built into the Linux kernel, the array worked perfectly for well over a year. A few weeks ago one of the hard drives had several errors and the operating system marked it as bad and removed it from the array. The array still worked and there was no loss of data, however I needed to replace the bad disk as a RAID 5 array can only lose one drive before permanent data loss occurs.

I ordered a new drive as I didn’t want to wait for the warranty on the current one to be processed, and within a week I had a new drive which was the exact same size and had the same number of logical blocks as the old one. I removed the old drive, placed the new one in and used the Linux mdadm tool to rebuild my array.

After using fdisk to create a RAID partition on the new hard drive, I used the following command to rebuild the array: mdadm -a /dev/md0 /dev/sdb where md0 was my raid device and sdb the hard drive that had failed.

By reading the contests of /proc/mdstat I could actually watch the hard drive slowly being rebuilt.

Personalities : [raid5] [raid4] 
md0 : active raid5 sdb1[6] sdg1[5] sdf1[4] sde1[3] sdd1[2] sda1[1]
      1562842880 blocks level 5, 256k chunk, algorithm 2 [6/5] [_UUUUU]
      [==========>..........]  recovery = 53.0% (165942648/312568576) finish=145
.3min speed=16814K/sec
      
unused devices: <none>

The FexEx delivery van pulled up with the new hard drive as I was about to leave for work. I decided to be a few minutes late so I could go ahead and install the new drive. It took less than twenty minutes and when I got home at the end of the day, the array was fully restored.

Welcome Back Cotter

It has been a while since I’ve had a professional website. I took down my previous one when I was doing some rearrangement on my web host. I’ve been planning on replacing it with a new professional website for quite some time.

Although this site is far from complete, it does have an archive of most of my recent graduate school work, along with a complete resume and portfolio. In the next few weeks I plan on adding more of my previous assignments from my undergraduate work, various open source projects I’ve developed, a portfolio of websites I’ve created and some helpful scripts for Linux users.

I plan on using this site to address topics relevant to computer scientists, write helpful tutorials, share interesting research and display skills in my fields of interest.