Hi, when i am during install rhel5(Red hat linux enterprise 5) i not setup Raid drive. Than after finish installed, i only configure a testing raid, ok when i am create a raid partition,i am using command "mdadm" than i success create a level=0 raid device name is /dev/md0 in physical harddisk partition /dev/sda7 and /dev/sda8. After that i just want to remove this /dev/md0, i dont know what is the correct method to remove it, so i just use fdisk to delete partition /dev/sda7 & /dev/sda8. I reboot system, than i issue command # cat /proc/mdstat so no any raid infomation there.OK, now i want to create a raid level=1 , so i fdisk two partition /dev/sda7 & /dev/sda8 as fd(software raid), when i want to create the raid drive /dev/md0, but before i create why it automatic have the drive already on /dev/md0? i already remove using fdisk. Please teach me a way how to correctly remove software raid device like /dev/md0 ,/dev/md1 we are create.

Thank you.

try to use
$mdadm -S /dev/md0
if the device is appearing in
cat /proc/partitions meaning if md0 is listed in device list.