Boot from an add-on usb card

[TSM]

I'm perfectly aware, my plan may not be the best idea, but it's what I want to do

 

I've been thinking about creating a permanent unraid virtual machine on my unraid server.  I've read several postings about it, and I think I know how to do it.  Before buying stuff though, I wanted to be sure. 

 

Is it 100% always true that, you have to remove and then re-insert the vm's flash drive when you reboot the bare metal unraid server?  Otherwise the server doesn't know which one to boot from?  I'm thinking that may not be the case if you use an add-on usb card.   It's my understanding that it's not possible to boot from an add-on usb card. So therefore, it would seem fine to leave the vm's flash drive connected, if booting from the card it's plugged into is not possible.  Right?

 

And I was thinking about installing an add-on card usb controller anyway, cause my motherboard only has one controller, and I wanted to pass a controller through to the vm.   But then my problem is, is it possible to use a flash connected to that card for booting with kvm on unraid? 

 

I think I have 2 options at that point.  Spaceinvader's video on creating an unraid vm for testing describes a process where you copy the unraid boot files to a vhd, boot the vm from the vhd, and then the flash drive is only there for registration purposes.  Or, seems I remember seeing in a posting about esxi, where it said you could have the vm boot from plop, and plop would simply pass the rest of the boot process off to the flash drive.  That should work with kvm on unraid too right?  From what I recall, the plop method seemed better, because you didn't have to install unraid updates manually, you could use the tool built into the webgui.  

 

Am I missing anything, is my understanding of all this correct?  

Edited October 18, 2018 by TSM

[JonathanM]

6 hours ago, TSM said:

It's my understanding that it's not possible to boot from an add-on usb card.

Depends on the BIOS. Some motherboards my load USB drivers and parse add on cards.

 

The transition to UEFI boot support has changed the landscape for what a BIOS does and doesn't do.

[TSM]

This worked!!!  

 

It was a very difficult process, because at first whenever I'd passthrough the usb card to the vm, it wouldn't boot.  And when I say, "Wouldn't boot", literally it did nothing.  Only the initial bios screen would appear, no errors, nothing.  Seabios and ovmf were tried, every possible combination of settings was tried, nothing worked.  I knew the card itself worked because I could use usb devices attached to it with the bare metal unraid.  

 

Then finally, as a "Hail Mary" attempt I updated the bios on my supermicro motherboard.  Success!  With Seabios, ovmf gave an error that I can't recall, but at least it gave an error, which was progress.  Seabios after updating the bare metal bios, worked.  Trial version of unraid works fine, and I can leave the usb thumb drive attached, and reboot my server, and the correct thumb drive boots the bare metal.  Did it several times, and it worked each time.  So that parts good, but now I have a different problem.

 

I've been using a SUPERMICRO AOC-SAS2LP-MV8, card in my server for a couple of years.  Been very happy with it.  When I put my new server together, I had a larger case, so I bought another one for expansion, but never really needed to use it.  Now that I'm attempting to create a virtual unraid server, I thought I'd passthrough the 2nd card to the vm, so it could have "bare metal" access to the drives.  I'm having a hell of a time getting this to work, I guess cause I've got 2 identical cards.  I've been using the xen-pciback.hide command in my syslinux file to no avail.  When I get home tonight, I'll post the various specifics if anyone would like to help me

 

 

[JonathanM]

2 hours ago, TSM said:

I've been using a SUPERMICRO AOC-SAS2LP-MV8, card in my server for a couple of years.

That is a marvell controller based card, which doesn't always work very well with the later versions of unraid. I suggest selling them while there is still a market for them and getting LSI controller based HBA's.