Comment 29 for bug 1475166

All that patch appears to do is to remove an artificial limit for all devices to 1024. I haven't been able to reproduce the option reset on my systems, so here is what I would try:

Try setting the controller option and see if that sticks [1]:
rmmod megaraid_sas
modprobe megaraid_sas max_sectors=2048

It may also be possible to do this while booting as a kernel command option like: megaraid_sas.max_sectors=2048
(2048 does actually mean 1024 for the other options).

Otherwise, I'd recommend switching to a Live CD and see if the option works there.

If not, a last option would be to try using sysfs on the livecd to see if that will help ensure it:
sudo add-apt-repository universe
sudo apt update
edit /etc/sysfs.ctl adding block/xxx/queue/max_sectors_kb = 1024
sudo apt install sysfsutils
sudo service sysfsutils restart

[1] http://fendertech.blogspot.com/2013/04/how-to-increase-maxsectorskb-for.html