FW: mke2fs does not like more than one device??

I'm trying to create a filesystem with more than one device. Any thoughts on what block count I should use? Tia. nvlnxt22:~ # mke2fs -j /dev/dasde1 /dev/dasdf1 /dev/dasdg1 /data mke2fs 1.28 (31-Aug-2002) mke2fs: bad blocks count - /dev/dasdf1