Oracle Database Discussions

I've been trying unsuccessfully to get something to work, without success so far. After the hurricanes of recent years we realized that with widespread power outages and network problems, being able to put our database on standalone laptops would be very useful for our field people. The full database is too large, but if I exclude the stored documents, it becomes manageable. Unfortunately, my management wants to have the option of including some documents. My thought was to create a separate tablespace to hold just that table, and put the tablespace on a USB hard drive, so if the field scientist didn't want the documents, they could just leave the external hard drive in the office. But I can't create the tablespace to test this out - I keep getting an ORA-27044 "unable to write header block" followed by "There is not enough space on the disk". I'm trying to create a 10GB tablespace, the external drive has 300GB free. Am I running into a Windows/USB restriction?

(I know there would be a problem with not having the tablespace available if the field guy didn't take the USB drive, but I'm trying to get past this problem first)

Thanks,
Harry