Having the same problem with debian, it might not be ubuntu related. I have checked all the scsi*.udev packages and so far failed to find the mpt2sas.
Solution I used was to extract the /lib/modules/<kernelversion>/kernel/drivers/scsi/mpt2sas/* and place them in the initrd.gz file.
Note: I use PXE booting so changing the initrd file was relatively quick.
Note: last installer checked used kernel 2.6.30
Having the same problem with debian, it might not be ubuntu related. I have checked all the scsi*.udev packages and so far failed to find the mpt2sas. <kernelversion> /kernel/ drivers/ scsi/mpt2sas/ * and place them in the initrd.gz file.
Solution I used was to extract the /lib/modules/
Note: I use PXE booting so changing the initrd file was relatively quick.
Note: last installer checked used kernel 2.6.30