killall hbwd causes sda to disappear

[uicguy]

I plug in my Pogoplug pro and ssh into it. After I login I do:

cat /proc/partitions
major minor #blocks name

31 0 131072 mtdblock0
31 1 14336 mtdblock1
31 2 116736 mtdblock2
8 0 7828480 sda
8 1 7828464 sda1

You can see my 8 GB thumbdrive. I can format the drive at this point:

/ # /sbin/fdisk /dev/sda

The number of cylinders for this disk is set to 9242.
There is nothing wrong with that, but this is larger than 1024,
and could in certain setups cause problems with:
1) software that runs at boot time (e.g., old versions of LILO)
2) booting and partitioning software from other OSs
(e.g., DOS FDISK, OS/2 FDISK)

Command (m for help): p

Disk /dev/sda: 8016 MB, 8016363520 bytes
154 heads, 11 sectors/track, 9242 cylinders
Units = cylinders of 1694 * 512 = 867328 bytes

Device Boot Start End Blocks Id System
/dev/sda1 1 9242 7827968+ 83 Linux

If i then do this command:

killall hbwd

After that command I now look at the partions I see this:

/ # cat /proc/partitions
major minor #blocks name

31 0 131072 mtdblock0
31 1 14336 mtdblock1
31 2 116736 mtdblock2

and if I now do fdisk I get this:

/sbin/fdisk /dev/sda
fdisk: can't open '/dev/sda'


What am I doing wrong? Why does the thumbdrive disappear? Sorry if a newbie questions could not find anything about this issue that was helping me