I just had a chance to install Ubuntu Edgy on HP NetServer LP 1000r: a 1U unit equipped with HP NetRAID 1M controller, which caused the most grief.
The situation was simple: megaraid drivers used by default kernel panic at random points during installation: sometimes right after boot, sometimes during partitioning, sometimes toward the end of the installation.
The real solution would be to fix the new megaraid drivers in the Linux kernel source, but I don't have the time nor knowledge to do so at the moment (though, knowledge can be acquired over time :). The workaround is to use the megaraid legacy driver, which is already shipped by Ubuntu.
The only slight problem is that it still doesn't recognize the HP NetRaid 1M controller as the supported one, so the module is not loaded, and loading it manually doesn't help. I've used a patch from SUSE Linux Rants to make megaraid.c and megaraid.h from linux-source-2.6.17 recognize the controller (which just adds the corresponding list of PCI IDs to the driver).
The tricky bits have now been to add this to installation media, and I decided to go with Live CD instead of the Server Install CD, since it was simpler, and I don't mind having full desktop on the server as well.
Following the instructions on customizing Live CD, I've extracted
Linux source there, got the megaraid.c and megaraid.h files out of it,
patched them with the above mentioned patch, put it all into a
/root/tmp (inside edit/—extracted filesystem) with some include files,
and built the module megaraid.ko,
putting it into
instead of the old legacy one, and removing all the new ones from
(to avoid panics since they'll still be loaded).
To build the driver, one can use
modules command if the above archive was extracted inside
/usr/src/megaraid (see RHEL4
After doing that, I've also added "megaraid" to the /etc/initramfs-tools/modules, and rebuilt the initrd using instructions on Live CD customization page.
Finally, I've constructed a Live CD, tested it with qemu, and then booted and installed the server off it. Finally a fully working system (everything else was recognized automatically). I can provide the ISO image for those interested, but it would be better if someone created an ISO image for ubuntu-server installation instead.
The bug about missing megaraid support is bug #82124 in Launchpad.
Warning: note that if you update your linux-image package, you'll again end up with new-style megaraid drivers being loaded, and the old-style being overwritten with the one without support for the NetRaid PCI IDs.
The instructions here should help for both HP NetServer LP 1000R and 2000R.