onspaces question

I dont know if my last mail went out or not so here it is again. I am new to informix so forgive the stupid question. I have installed Informix on NT(evaluation copy). I was trying some experiments on it. I mirrored the logspace and deleted the primary device file. When I brought the db server up it had marked the primary chunk as down. I read from the manuals that in order to stop mirrorring I use onspaces -r. If I do that I get the message "unable to change status of chunk". So I tried to change the status of the chunk using onspaces. I get the message "the specified chunk does not exist". What did I do wrong? Also, if say because of a permission problem or some such thing, the device is not ready when informix starts, it marks the chunk as down. Now how do I get that chunk online? onspaces simply does'nt work. TIA Deepa