even if usb-storage is loaded with rdloaddriver= before starting udevd, the device is not recognized as sda

Issue

• We want the usb device recognized as sda on boot, but it's recognized as sdb.
• dracut package still has mkinitrd command, and it has --preload option. The option was used.to load a driver before loading other drivers on Red Hat Enterprise Linux 5. But, it doesn't work like it on Red Hat Enterprise Linux 6.
• Instead of it, rdloaddriver= boot paramater can be used to load a driver before udevd starts in initramfs on Red Hat Enterprise Linux 6.
• But, even when rdloaddriver=usb-storage is used, the usb device was recognized as sdb, not sda.