Building indexes -- help

I continually run into device full messages when trying to build an index. Can anyone help? I an running 7.10 UD2 on an SGI Challenge. I have 3 dataspaces. The first one has 4, 1Gbyte chunks, the other 2 have 3, 1 Gbyte chunks. I have a 3, 1 Gbyte chunk tempspace. My root space is the small 20Mbyte default. I have one database which is not logged. Hence the small rootspace. The database was assigned to the first database space which has 4Gbytes in it. In this database I have built a large table with 10m plus rows. I fragmented the table round robin. The rows are about 300bytes long. One column is varchar (100,28). I have a primary key index, which I presume has been built in the first space. And I managed to create another index on an int column with a hashing fragmentation strategy using the MOD function. I am now trying to create an index on the varchar(100,28) column. Whatever fragmentation strategy I use to place the indexes where I think I have space to put them I get a device full messsage. I can not determine which device is full--how do you determine which device is full? I have written a small C program to create the index and tried to collect the error messages using exp_chk -- no help, a specific name is not returned. I am runing oncheck -pT database -- this seems to create a stink load of processes, run forever and lock up the machine. The info from onmonitor says I am using 1.5 gig out of 3 gig in each of the 2 smaller spaces, and using about 2.6 gig of the 4 gig in the first dataspace. If the create index does a sort it will need about 10m x 100bytes / 2 in tempspace (if it sorts the index in temp space) therefore I guess I have enough temp space. I think I need about 1.2 gig to store the index, I have specified different fragmentation strategies to place the index equally in each of the spaces but whatever I try -- no space left on device. Help.