Comment 17 for bug 1475166

1) I would at least try booting multiple times.
If possible I would try partitioning so you have extra space and can set up a new ext4 partition on the Controller for every test. Then deleting before running the next one.

In fact, I'd recommend for the next test to install 15.04 on a SATA drive in the system and see if you can reproduce with the controller just doing the above. Try reproducing it at least 3 times to be sure it freezes every time.

Then if you do another Git Kernel build (v3.19) it will use 15.04s config by default (as well as the new compiler). This would help rule out it being an Ubuntu specific patch (or prove that it is). Please do post the 14.10 config from your GitKernelBuild so we can see the full working config you used.

 2) There is no specific raid or ext4 change that I've been able to find so if we can narrow it more that would help.

Another useful data point would be to try a wily development image (will be 15.10) - http://cdimage.ubuntu.com/ubuntu-server/daily/current/.