how to disassemble / destroy a raid
 

hello everyone!
how can i disassemble a raid 5 partition?
basically i have 3 x320GB hd's at the moment in raid5.. thats sdb1, sdc1 and sdd1..
i am just in my initial steps with raid.. and i managed to get a hold of a 4th identical drive..
so im reading that i could add it with mdadm --grow..
but since i haven't written anything on the drives yet.. i could just destroy this raid.. and make a completely fresh one..

an additional reason is that having not done that before in the current raid i did not use the --force option thus mdadm decided to create a raid 5 (out of my 3 drives) one of which is labeled 'missing' and used as a spare instead...
that results in having only 2 active drives in raid 5 which in turn means i only get 1/3 of the space i have. ie df returns to me 320GB for /dev/md0 node instead of 640GB that it should (2/3 x total size).

so how can i go about destroying the raid table or whatever else so that i can start the raid again from scratch?
thank you for your help
nass

Reformat each drive with fdisk.

before you go ahead, i'd write some data to the disk, and try to add extra drive the the grow command and see if it works. then experiment with it a little bit before you actually put it to work. might save you a lot of troubles in the future. just a suggestion.