MAKEDEV generates SCSI generic devices with a letter: /dev/sga, /dev/sgb, ... The man page MAKEDEV(8) says that "the devices created are sg0 through sg7". The "Linux Allocated Devices" document (ftp://ftp.kernel.org/pub/linux/docs/device-list/devices.txt ) in the kernel source Documentation says that it should be /dev/sg0, /dev/sg1, ... Other Linux distributions already set it to sg0, sg1... To keep a compatibility with previous version, an idea would be to use symbolic links.
Well, there hasn't always been agreement on the right set of names, but it makes sense to get the most compatibility with the most software by having both sets of names.
Will be fixed in MAKEDEV-2.4 and dev-2.7.1