You perhaps won't succeed with a file > 4GB. There were some limits with fseek or such as far as I remember.
On 64-bit Linux the limit is 2^63 as filepos and I guess on 32-bit Linux 2^31 (at least, but depending on size of data_type long), but already the (official) 193000-bootstrap file has > 2GB size.
Appendum: I should add: Really it depends on the filesystem you are using. I talked about Ext-2, Ext-3 and Ext-4 FS - (the default Linux filesystems).
smtp