I thought I would document my successful install of Rockstor 3.9.0 on a new Dell T330 server, as it was quite involved.
I wanted this server to use UEFI instead of BIOS, and install on a 120GB SSD (the server also has 4 6TB drives installed).
I first burned a 3.9.0 DVD and attempted to boot from it. This boot failed with the dreaded:
dracut-initqueue: Warning: dracut-initqueue timeout - starting timeout scripts
message displayed repeatedly before dropping to the emergency mode terminal. Same for 3.8.16.
3.8.15, however, booted to the install without issue, and I was able to install Rockstor as normal. Upon reboot though it appeared that the server had hung - no activity on the network, and the screen never reached the login prompt, just a mostly blank screen. I rebooted and removed quiet from the kernel parameters and saw that the screen froze after switching from the simple fb driver to mgag200drmfb. After some fiddling with kernel parameters, adding:
nofb nomodeset
prevented this from occurring and I reached a local login. (this was then added to /etc/default/grub and I ran grub2-mkconfig -o /boot/efi/EFI/centos/grub.cfg to make it permanent).
After digging around, I found that the rockstor init script was not running because the network interfaces had not been configured. So I went to /etc/sysconfig/network-scripts and edited ifcfg-em1 and ifcfg-em2 setting ONBOOT=yes , then rebooted. The bootup then failed, something about the mei_me driver not initializing. I had to restart in single mode and remove my changes from the network scripts in order to get the system back up.
When it did come back up, I quickly logged in and enabled em1 (ifup em1). The rockstor init script then ran and I could connect to the system and finish the install. I upgraded to 3.9.0 using the web interface without issue. After a restart, I re-enabled the em1 and em2 ONBOOT setting and I now have a stable server with no apparent issues.
Hope this helps someone.