[Novalug] Asking early... maybe ok Fedora + HW RAID

[greg pryzby]

On 11/25/2009 06:38 PM, Peter Larsen wrote:
> On Wed, 2009-11-25 at 17:57 -0500, greg pryzby wrote:
>> On 11/25/2009 04:36 PM, Peter Larsen wrote:
>> >  On Wed, 2009-11-25 at 15:56 -0500, greg pryzby wrote:
>> >>  I received a box w/ hardware RAID with Fedora 11. It worked great. I
>> >>  tried to preupgrade and on reboot I got a mismatched size error. So I
>> >>  googled to see what could be going on w/o much info. There was an
>> >>  preupgrade in updates-testing that was recommended so I tried that, same
>> >>  issue. From looking at OS level, RAID looked ok.
>> >
>> >  What kind of"hardware"  raid? The hardware raid my box came with turned
>> >  out to be software and a lot worse that our md drivers. The problem you
>> >  need to be aware of isn't whether the kernel supports it, but if grub
>> >  supports it. Grub2 is supposed to have better support, but it's a lousy
>> >  documented project (it's included with Fedora - good luck is all I can
>> >  say). I had a simple RAID0 (stripe) and grub failed miserably
>> >  reading/understanding the raid on the system board.
>> >
>> >  If you're going RAID1 you may be more lucky since it shouldn't matter
>> >  what disk it chooses - unless there's truely a Hw raid signature on the
>> >  disk that'll confuse grub.
>>
>> 3ware 9650SE and it is supported in Linux, in the kernel. the crappy mb
>> raid isn't being used. pci-e card
>
> But is it supported by GRUB? What does Grub after phase 1 has loaded
> from MBR+boot?

I don't know. I will google.

I can tell you SLES 11 sees everything fine. ARG!

I am not getting to GRUB yet. I am installing and it is going to look 
for storage devices. That is when it dies in anaconda.

This time I tried to save the trace and the whole box froze.


>> I built RAID 5 via the firmware
>>
>> However, looking at dmesg, they talk about RAID 6, ok whatever.
>> shouldn't matter from a quick search.
>
> THAT should not matter if it's true hardware raid. The actual raid
> mechanisms are hidden from the OS/boot loader.

Agreed and ignoring

>> There are 2 partitions (is that the right term?). it asked in firmware
>> about boot size and it created 2 partitions.
>
> Sure could be. Same rules applies as a single disk. You need a boot
> partition. And something for the rest. Grub2 allows you to place the
> boot on LVM2 - so you don't need any partitions then. Can't wait!

Well, RAID setup (RAID 5) has a place to boot 'boot size'. I set that to 
something the first time. This time I am leaving it blank. Maybe that 
confuses the system?

There are 5 500GB SATA drives

> But your HW raid should NOT care at all about "partitions". If you're
> doing RAID 6 you have at least 4 disks of the same size and dimension.
> Your HW Raid should simply make a single disk-image (logical) out of the
> 4 disks and present this volume to the OS. The OS will then do what it
> usually does, with partitions and all (including MBR). In some cases,
> metadata about the RAID is stored on disks - but I wouldn't expect to
> see that in partitions. That should be hidden from you.
>
>> I think that maybe where things are wacky or maybe there is ONLY
>> hardware raid5 disks.
>
> The actual raid level should not matter if it's true hardware. What
> happened to my software card (I checked your card, it has a processor on
> it so it should be true hardware) was that once grub-stage 1 was over,
> it couldn't find the partition and it's data to boot from.

Off to look at grub, but like i said it isn't getting that far... just 
trying to find the storage disk

3w_9xxx is loaded (driver for 3ware card)

I hope by not setting boot size and taking all default setting for the 
RAID creation, it will work better.


-- 
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