FlowerPower

Indeed it seems to be, and you were just solving the same problem a month ago. Looks like the same setting fixed it. For the next person who searches, the solution to unraid not booting on a SuperMicro H8DGU(-F) motherboard, BIOS version 3.5c, with more than 11 drives is "go into the LSI configuration utility and change the adapter control from BIOS and OS to OS Only"

Well shit. On a hunch I pulled one the drives, which was added to the array but had no data on it yet. Sure enough, up pops the unraid boot screen. So I can boot with 11 drives installed, but not 12. I read about a similar issue with a different motherboard, where USB was being treated like a drive, and it broke once you hit 12. Even though USB is definitely a separate boot option in this BIOS, I seem to have a similar problem. This, needless to say, rather defeats the point of the 36 bay server. Any idea how I can get around it? MB s SuperMicro H8DGU(-F) version 3.5c, which appears to be the latest.

I finally got an error message. I took all the boot devices out of boot priority in BIOS except the USB drive and removable devices. If I do that, I get the below, with both my original USB drive and a brand new one. If I add back in the other devices, it goes back to the blinking cursor. It seems the server has stopped recognizing these as USB drives as bootable, although no changes should have happened in BIOS. What are the key BIOS settings to check for unraid? I am running a SuperMicro 36 bay server, a couple generations old. Motherboard is an H8DGU-F. I looked through every BIOS setting and don't see anything obvious. This is maddening. It worked perfectly through the whole trial period. Now that I'm licensed and have all my drives migrated, dead in the water.

Right, so I rebuilt the USB drive with the flash creator, copied over config--no change in behavior. Is there something in my config that could cause the boot process to not even start? I get no screen output whatsoever.

Yes, both a quick scan and /f, no errors found. I assume my next step is to rebuild the USB drive and then copy over the old /config directory.

SOLVED: unrelated to power loss. It is a BIOS issue that prevents USB boot with more than 11 drives installed. Solution: the solution to unraid not booting on a SuperMicro H8DGU(-F) motherboard, BIOS version 3.5c, with more than 11 drives is "go into the LSI configuration utility and change the adapter control from BIOS and OS to OS Only". I tried to boot my server this morning and all I get is a blinking cursor post-BIOS (monitor connected to the server). I checked boot order in BIOS, tried putting the USB drive in a different slot, nothing. I put the USB drive in my Windows box and it appears to be fine. I was able to copy all files as a backup. How do I get this thing booting again? It's not even starting to boot as far as I can tell. What happened prior: I just finished the initial setup of my server, and was transferring some files. The power went out, but the UPS appeared to do it's job and shut the server down after five minutes. The UPS didn't power off as I had it set to, so I shut it down manually. When the power came back on, I powered up the UPS, the server started and then...didn't boot. A number of changes had been made since previous shutdown and reboot. Three data drives added, two cache drives added, all shares except my media library set to cache only, Community Applications installed, Plex installed, and the UPS was set up. Everything was working perfectly, no warnings or errors.