DANGER!!! Problems with 10.04 installer (RAID devices *will* get corrupted)

[Dave Howorth]

Alvin Thompson wrote:
> On 04/22/2010 12:14 PM, Dave Howorth wrote:
>> You didn't think about what I wrote. The LVM is irrelevant. What I'm
>> saying is that my issue was caused by grub and I think there's a
>> possibility that #191119 is too. OTOH, I don't think it seems like your
>> problem is and it therefore seems a sensible precaution to leave the two
>> bug reports in place for separate investigation.
> 
> IIRC, grub only writes to the first few kilobytes of your drive, which 
> is not in any partition or data area, so that is very unlikely to be the 
> problem unless you're using an extremely old version of GRUB 1 which 
> can't handle large drives.

Hi Alvin,

Actually grub can write into partitions if it's asked to. Multiple
independent copies can be installed in the MBR area and into every
partition on a disk if you so wish.

Equally, you don't need to create any partitions on a disk to create an
LVM and I'm speculating that the same may be true for fakeRAID. They
just write to the /dev/sda device.

So there are possibilities for grub to write to the same area as
filesystem data in certain cases.

One other difference between #191119 and your report is that #191119 was
reported two years ago and so using grub 1, whereas your report
presumably uses grub 2. So that's at least one potentially significant
difference between the two report environments. For that matter, I
understand ubiquity has changed substantially between versions.

>> Until at least one of the problems is bottomed out so both the cause is
>> known (specific lines of code) and a fix is in place, nobody can be
>> absolutely sure they are the same bug.
> 
> I have already given steps on reproducing the problem.  Once the problem 
> is there, it stays there no matter how many times you try to install. 
> The only way to stop the problem once it's there is to physically zero 
> out any left over file systems on the disk.  This shows that it indeed a 
> problem with the left over file system.  It also proves that it's not a 
> GRUB problem because if it were, the problem would continue because all 
> you did was zero out a file system which no longer existed in the first 
> place.  I'll cut you some slack on this one, because I didn't mention in 
> my previous posts how I fixed the problem.

I understand that your problem has to do with a left over filesystem and
I also agree that it probably isn't a grub problem. But I also believe
that a grub problem *is* a possible explanation of #191119. Which would
mean that the two are different problems, not duplicates.

Which is why I still think it is premature to mark them as duplicates.

Reading the thread, it seems like your reason for marking them as
duplicates is not for technical accuracy but a political opinion that
they will get more attention if marked as duplicates. If so, I
understand your motivation and I simply don't know what rule to use to
form an opinion as to whether it is 'right'.

Cheers, Dave