[SOLVED] Move boot to USB


Sep 30, 2019
I've acquired a few new (to me) HP DL380p G8 servers and plan to get a Proxmox cluster installed on them. These have the infamous P420i RAID controllers in them which will not boot from HDD when in HBA mode. I've done a bunch of research and know other people are successfully doing what I am trying to do, but for some reason I'm not having any luck.

I'd like to have the server boot from a usb key to get around the P420i limitation and then run ZFS on drives on the P420i in HBA mode. My understanding is this is not ideal, but should be okay since the high read / write will be on the HDD and not on the USB which is only used to boot.

I've successfully installed Proxmox on an SSD in ZFS RAID0 attached to the P420i in HBA mode. When I reboot, it won't boot (obviously). Then I boot into the Proxmox installer (debug mode) and attempt to get proxmox-boot-tool to write the boot files to the USB, but it's not working.

I've tried following the steps here (Proxmox install on non-bootable disks (HP DL 380p G8 with P420i switched to HBA mode) and bootable SD-Card : Proxmox (reddit.com)) and several variations of it from different sites to get proxmox-boot-tool to write the bootloader to the USB. It appears to work when I run proxmox-boot-tool format /dev/sdb1 and proxmox-boot-tool init /dev/sdb1, but when I attempt to boot from the USB I'm dropped into a GRUB prompt. When I snoop around GRUB with "ls" I cannot find any files on the drive. I see (hd0), (hd0,gpt1), and (hd0,gpt2), but no files. It's like proxmox-boot-tool isn't actually putting the right files on the drive to boot the OS.

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Did a reinstall of Proxmox using exactly the same method / setup. Followed the instructions in the reddit post linked above and this time it worked flawlessly.

I suspect one of the "other variations" I tried to get the USB to boot did something to make this not work.


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