- if ((!total_size || total_size == -1ULL) && !td->o.size &&
- !(td->io_ops->flags & FIO_NOIO) && !td->o.fill_device) {
- log_err("%s: you need to specify size=\n", td->o.name);
+ if ((!total_size || total_size == -1ULL) && !o->size &&
+ !(td->io_ops->flags & FIO_NOIO) && !o->fill_device &&
+ !(o->nr_files && (o->file_size_low || o->file_size_high))) {
+ log_err("%s: you need to specify size=\n", o->name);