Hi, First thing I did was a bios update so I'm on 2.2.5 which should be the latest. The 2 mirrored disks are 1.8TB 10K RPM SAS 12Gbps 4Kn 2.5in Hot-plug HardDrive. The GPU did not ship with the systemThe processor is E5-2660 v4  I've now narrowed the problem down to the disks. I mentioned that I had other R730 nodes that do work. Those nodes have these drives: 300GB 15K RPM SAS 12Gbps 2.5in Hot-plug HardDrive,3.5in. I took 2 of them out of the working systems and raided them together in my non-working system and that solves it. So I think that it is the combination of 4Kn size on the 1.8TB and UEFI turned off that confuses the bios and prevents the disks from appearing as bootable.Now that I start google searching for the correct terms I come up with this: [URL] on page 10 it confirms that 4Kn is only supported in UEFI mode. Thanks for your time!
Hi, I have an R730 with all firmware recently updated to latest versions in an attempt to resolve this problem. I need to host an Nvidia K20 (slightly older but qualified GPGPU). I therefore have UEFI turned off I have 2 disk drives in a mirror raid (1) and set to writeback and no read ahead (for the purposes of troubleshooting this problem). I can boot from USB and install CentOS to the Virtual Disk but the Virtual Disk does not appear in the menu of bootable devices. If I re-enable UEFI then the disk appears in the list of bootable devices (but the GPU crashes the system before the boot - crash looks something like this: [URL] I also have 3 other R730s that only have a single disk and no raid controller. They all work by simply turning off UEFI and making no other changes.  
Raid controller not presenting bootable VD