Force to drop a chunk ?

Dear All : My platform is IDS 9.21 running on Linux OS. I made a careless mistake to delete a chunk file , then I try to drop that chunk from the dbspace that it belonged to : onspaces -d tmpdbs -p /data/tmpdbs_chunk2 -o 0 But the system gave me an error message and did not allow me to do that. The message is : Chunk not dropped. ISAM error: Primary and Mirror chunks are bad Does anyone know how to resolve this ? I do hope to drop this missing chunk from dbspace. Thanks in advance. Ken