Re: [Etherboot-developers] Q: Multiple drivers.

[Peter L. <P.L...@sy...>]

> >Anyway, REQUIRE_VCI_ETHERBOOT makes you ignore the ISP, no?
> 
> It's wrong to require a special option to handle a common situation.
> See below.

Hmm. I don't regard REQUIRE_VCI_ETHERBOOT as a "special" option, I must
admit. I concede that it's not the ideal way to handle this, but the
point still applies that where one has a choice of networks, it's better
to distinguish nics based on which network they really are connected to,
rather than whether the slot order is still the same and you
accidentally reversed the cables.

> It's not that it's obviously right to use the same NIC, it's obviously
> wrong to boot another NIC from this ROM. If I move the NIC with the ROM
> to another machine I may get a different boot behaviour. No good.

Why not? It's now a different *machine* after all - seems likely that
different boot behaviour is exactly right - e.g. boot using a built-in
network interface (which identifies the machine better than an movable
nic). The BIOS also makes a difference, as I mentioned.

Let's not lose sight of the fact that I want to boot a machine: the nic
offers a network medium, a unique ID and possibly some flash rom. nics
are fairly mobile anonymous entities in our development servers, so I
definitely favour predictability of behaviour over any idea that
particular nic is specially honoured.

> No, if I put the ROM on this NIC, I meant to boot this NIC, not another.

Maybe *you* do, Ken. I don't.

> This is one situation where I have indicated my intent. If I boot from
> floppy or BIOS ROM, my intent has not been fully indicated and some
> other behaviour is plausible. If your intent is for the flash memory on
> the NIC to be a general purpose BIOS extension area, fine, but you
> should have to select that compile option.

Again, I beg to differ. I have been using Etherboot from nic flash, but
we are now using it from LILO on most of the development machines. I
started off with floppy, and we've used PXE in response to test site
feedback and because it's a useful "out of the packet" solution. All of
these systems have multiple NICs and I assure you that at no time did I
ever consider changing the boot medium for administrative convenience to
be a partial or full statement of intent of which nic to use. I just
appreciated the fact that Etherboot always worked in the same way.

> Glad we agree. I look forward to your code. :-)

We agree that our requirements are different. I concede that Sychron
probably represents the extreme end of multi-nic cluster booting. Vasil
and I are agreed that when I was looking for a netboot solution for
Linux, with PXE as an essential requirement, we could have gone for
pxelinux, GRUB didn't seem stable but Etherboot seemed like the right
choice - the work involved in Etherboot via PXE has been amply
justified.

Code? Well, it may happen before too long. :) Sychron's in the middle of
getting a product together, and booting - by whatever means - is a part
of this. I've been keeping an eye on LinuxBIOS as well, and Eric
Biederman's recent work on integrating Etherboot and LinuxBIOS, and the
IDE polling drivers would be very applicable to us.