Comment 6 for bug 1407714

------- Comment From <email address hidden> 2015-01-21 18:25 EDT-------
(In reply to comment #9)
> (In reply to comment #8)
> I think Dave may not have been clear enough.
>
> The issue isn't trying to find the netboot ISOs. We get those just fine by
> following the normal links at http://cdimage.ubuntu.com/netboot/vivid/:
>
> e.g., to
> http://ports.ubuntu.com/ubuntu-ports/dists/vivid/main/installer-ppc64el/
> current/images/netboot/
>
> The issue is that, the DVD iso:
> http://cdimage.ubuntu.com/ubuntu-server/daily/current/ on ppc64el does not
> allow for netbooting. It is missing some drivers in the initrd, but also
> even when said kernel/initrd is netboot'd, it attempts to install off the
> DVD. I have seen this for all ppc64el releases of Ubuntu when installed via
> Cobbler. A workaround (which I've been using for some time) is to use the
> vmlinux/initrd.gz from
> http://ports.ubuntu.com/ubuntu-ports/dists/vivid/main/installer-ppc64el/
> current/images/netboot/ubuntu-installer/ppc64el/ to override Cobbler's
> notion of Ubuntu's kernel/initrd pair.
>
> From what Dave has told me offline, though, x86 doesn't suffer from this
> particular issue. The same ISO can be used to install from the disk tray or
> over the network.
>
> Thanks,
> Nish
>

Exactly. Here is a list of initrd files on amd64, powerpc and ppc64el ISOs, respectively. We notice the amd64 disc has an additional initrd specifically for netbooting, not present on the powerpc and ppc64el discs. The initrd on the powerpc and ppc64el discs are missing some or all of the required network drivers. On the ppc64el, I notice some of the drivers (e.g. ibmveth, tigon3) are built into the kernel and so do not need to be on the initrd. Even so, it's missing quite a lot. Like the powerpc64 case, there are a boatload of drivers in the "netboot" initrd that are not in these initrd.

$ find ./ubuntu15.04/ -name initrd.gz -exec ls -lh {} \;
-r--r--r-- 1 root root 9.9M Jan 13 01:46 ./ubuntu15.04/amd64/install/initrd.gz
-r--r--r-- 1 root root 22M Jan 6 20:10 ./ubuntu15.04/amd64/install/netboot/ubuntu-installer/amd64/initrd.gz
-r--r--r-- 1 root root 8.1M Jan 13 17:49 ./ubuntu15.04/ppc64/install/e500mc/initrd.gz
-r--r--r-- 1 root root 8.0M Jan 13 17:49 ./ubuntu15.04/ppc64/install/powerpc/initrd.gz
-r--r--r-- 1 root root 8.5M Jan 13 17:49 ./ubuntu15.04/ppc64/install/powerpc64/initrd.gz
-r--r--r-- 2 root root 9.3M Jan 13 17:49 ./ubuntu15.04/ppc64el/install/initrd.gz

(It's easy to see that the "netboot" initrd for PPC, not shown here, are about twice the size of the ones on the ISO).

So the question is, why not put the netboot initrd on the powerpc and ppc64el ISO as they are for amd64? If no good reason, can we get them added? Thx.