Re: SATA, RAID, A8N-E, 3800+ help
Keith Ballantyne wrote:
>
>> For the 31r1a to recognize your network, if it went as in my case, the
>> installer shouldhave proposed you with a list of network modules. You
>> have to choose something call nforether,I believe.
>
>
> Thanks. the 31r1a installer works with the nForce2 network card
> 10/100 driver on my asus a8n-e.
>
> So, I've installed about 6 different ways, utltimately arriving at
> some critical error somewhere along the way.
> I've read most of the faq/helps/howtos and archives that I could find,
> and I still have the same problem.
>
> I want to use RAID0 for the bulk of my file system. I would like to
> even use RAID0 for my boot and swap partitions.
I suspect using raid0 for /boot is a non-starter: afaik GRUB can only
load things from a single device. Using raid1 for /boot and raid0 for
everything else would simplify things, I hope. Having said that, I've
not actually used raid for booting off myself, I've just had to debug
GRUB-not-booting-again problems several times :|
> I followed the instructions outlined at
> http://www.howtoforge.com/linux_software_raid?from=10&comments_per_page=10
> and got further than ever before, but couldn't successfully install
> either GRUB or LILO.
>
> The article above suggests 4 raid partitions
> /boot (50M)
> /swap (1G)
> / (10G)
> /var (the rest)
>
> It is also written specifically for RAID1, though it implies that
> doing the same for RAID0 would work. I'm worried because I'm unsure
> if the MBR is 'striped' in RAID 0, or if the MBR's of each of my 4
> drives are exempt. Regardless, I've tried it three ways:
If you're using md within partitions the MBRs are exempt, because
they're outside all partitions. But when booting, grub will load most of
itself from the /boot filesystem, wherever that is. It will embed part
of itself in some "empty space" at the head of the filesystem (as I
understand it) and the remainder will be loaded by navigating the
filesystem itself. The code to load the embedded bit is very simplistic,
and doesn't appreciate the difference between sda1 and md0.
>
> case 1: /boot as a specific 50M partition, on the 1st SATA drive
> (ext3)
> case 2: /boot as a RAID1 collection of the first 50M worth of all 4
> SATA drives (ext3).
> case 3: /boot as a RAID0 collection of the first 50M worth of all 4
> SATA drives (ext3).
> note: In all 3 cases, the remainder of the drive was configured as
> a RAID0 array, and I used LVM (1 volume group) to created two logical
> volumes, a 4G swap volume and the rest (to mount as /).
>
> case 1: allowed me to complete installation, grub appeared to install
> okay, but it doesn't boot, I just get a blank screen.
Very odd-- so you never get any of the "stage1 loading..." messages or
anything? This really should have worked. Or did the screen go blank as
it was booting and then not unblank? (Just as a matter of interest--
does installing without raid work at all? How about using the installer
as a rescue disk, does that work?)
> case 2: the partitioner seemed to change the partition types, and
> would never let me install GRUB.
Ick. Presumably the partition types got changed to the "raid autorun"
type to be used by the kernel's own md bootstrapping code.
If you have sda1 and sda2 as md0 (raid1) then you should be able to
install grub to sda1 directly. However, persuading it to do this from
inside Linux is convoluted-- you have to rewrite the device.map to
specify that (hd0) is sda, which is presumably the reason for the
installer not doing this for you.
An alternative approach is to make a grub floppy[1], boot that, and then
setup grub from there-- just do "root (hd0,0)" and "setup (hd0)". You
need to have grub "installed" as in the files need to be in /boot/grub/
for the setup command to work. Presumably you won't have a useful
menu.lst file, so you'll have boot the system "by hand" at least the
first time-- after "root (hd0,0)" you need to do "initrd
/initrd.img-whatever" and "kernel /vmlinuz-whatever root=/dev/md0" and
then "boot". Not sure what parameters you may need to give to the kernel
to get md0 automatically assembled-- "md=autorun"?
Istr it days gone by there was a "build a boot floppy" option. Has that
gone now?
[1] which you can do with just dd from the shell while installing. A
grub boot floppy is a terribly useful thing to keep around btw. From
memory: "dd if=/boot/grub/stage1 of=/dev/fd0 bs=512" and then "dd
if=/boot/grub/stage2 of=/dev/fd0 bs=512 seek=1".
SRH
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