Comment 0 for bug 1648388

Install Ubuntu16.04 in RAID1 created by Intel RSTe no matter legacy mode or UEFI mode.
System hangs while rebooting

Not found the issue in RAID0
No issue on Ubuntu14.04
Driver-OS inbox support

Below as error messages
===================================================
INFO: task systemd-shutdow:1 blocked for more than 120 seconds.
            Not tainted 4.4.0-21-generic #37-Ubuntu
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

INFO: task jbd2/md126p2-8:1732 blocked for more than 120 seconds.
            Not tainted 4.4.0-21-generic #37-Ubuntu
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

INFO: task ext4lazyinit:1873 blocked for more than 120 seconds.
            Not tainted 4.4.0-21-generic #37-Ubuntu
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

INFO: task kworker/u66:4:3139 blocked for more than 120 seconds.
            Not tainted 4.4.0-21-generic #37-Ubuntu
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
===================================================

Then I edit /etc/sysctl.conf with follow commands and the system don't hang while rebooting

vm.dirty_background_ratio=5
vm.dirty_ratio=10
kernel.panic=3
kernel.hung_task_panic=1
kernel.hung_task_timeout_secs=30

But I don't know if it's an appropriate fix or not.

Thanks