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### failed to boot into RAID-5 root filesystem in Ubuntu 8.04

Mulyadi Santosa [mulyadi.santosa at gmail.com]

Fri, 4 Sep 2009 21:46:28 +0700

Hi Gang...

Today I try to setup a server using Ubuntu 8.04. This PC has 3 hard disks and I plan to bond them as RAID 5 device.

To achieve that, during setup stage, I create 6 partitions. 3 of them are clustered as RAID 5 and mounted as /, while the rest are also made as RAID 5 device and formatted as swap.

There was a warning telling me that those new RAID devices won't be recognized until I reboot the machine. I hit the Continue button and proceed with package installation etc. Everything seems OK and finally the installer ask me to remove the DVD and reboot.

Here comes the trouble, the freshly installed Ubuntu won't boot. My partner told me that it could due to unfinished RAID synchronization. So again I boot the Ubuntu DVD, this time I pick "rescue mode" and go into shell (making /dev/md0 the root fs). In this shell, I did "cat /proc/mdstat" and found out the sync is still on the way. So I wait until it hit 100% and reboot the machine again. But still, no luck.

Thus, I wonder, is this because I pick RAID 5 device as root fs? Is this a known bug (or limitation of GRUB)? I came to this conclusion after reading http://advosys.ca/viewpoints/2007/04/setting-up-software-raid-in-ubuntu-server/ (the 8th comment).

Advices are greatly appreciated. Thank you in advance for your attention .....

    --
    regards,

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Kapil Hari Paranjape [kapil at imsc.res.in]

Sat, 5 Sep 2009 06:28:37 +0530

Hello,

On Fri, 04 Sep 2009, Mulyadi Santosa wrote:

    > Thus, I wonder, is this because I pick RAID 5 device as root fs? Is
    > this a known bug (or limitation of GRUB)? I came to this conclusion
    > after reading http://advosys.ca/viewpoints/2007/04/setting-up-software-raid-in-ubuntu-server/
    > (the 8th comment).

Indeed. AFAIK, grub (grub1) cannot boot from RAID or LVM partitions. It needs a file system on a "standard" block device. Your best bet is to install grub-pc (grub2) and see if that works for you. grub2 is soon to become standard for Debian and Ubuntu.

The other option is to switch to Lilo.

Regards,

Kapil. --

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Thomas Adam [thomas.adam22 at gmail.com]

Sat, 5 Sep 2009 02:06:31 +0100

2009/9/5 Kapil Hari Paranjape <kapil@imsc.res.in>:

    > The other option is to switch to Lilo.

... which won't work.

-- Thomas Adam

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Kapil Hari Paranjape [kapil at imsc.res.in]

Sat, 5 Sep 2009 06:56:23 +0530

Dear Thomas,

On Sat, 05 Sep 2009, Thomas Adam wrote:

    > 2009/9/5 Kapil Hari Paranjape <kapil@imsc.res.in>:
    > > The other option is to switch to Lilo.
    >
    > ... which won't work.
    >
    > -- Thomas Adam

Thanks for pointing out the error of passing on unverified information vaguely remembered from diverse readings on the 'net.

Kapil. --

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Mulyadi Santosa [mulyadi.santosa at gmail.com]

Sat, 5 Sep 2009 19:04:17 +0700

Hi everybody....

On Sat, Sep 5, 2009 at 8:26 AM, Kapil Hari Paranjape<kapil@imsc.res.in> wrote:

    > Dear Thomas,
    >
    > On Sat, 05 Sep 2009, Thomas Adam wrote:
    >> 2009/9/5 Kapil Hari Paranjape <kapil@imsc.res.in>:
    >> > The other option is to switch to Lilo.
    >>
    >> ... which won't work.
    >>
    >> -- Thomas Adam
    >
    > Thanks for pointing out the error of passing on unverified
    > information vaguely remembered from diverse readings on the 'net.
    >
    >
    > Kapil.
    > --

OK, I found more information about it. According to a user post in: http://ubuntuforums.org/showthread.php?t=714798, it seems that RAID-1 as root filesystem works, whereas RAID-5 won't.

I haven't tried it because I am away from the experimental machine, so is there anyone who can confirm the above posting? Thanks in advance...

    --
    regards,

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Thomas Adam [thomas.adam22 at gmail.com]

Sat, 5 Sep 2009 13:07:00 +0100

2009/9/5 Mulyadi Santosa <mulyadi.santosa@gmail.com>:

    > Hi everybody....
    >
    > On Sat, Sep 5, 2009 at 8:26 AM, Kapil Hari Paranjape<kapil@imsc.res.in> wrote:
    >> Dear Thomas,
    >>
    >> On Sat, 05 Sep 2009, Thomas Adam wrote:
    >>> 2009/9/5 Kapil Hari Paranjape <kapil@imsc.res.in>:
    >>> > The other option is to switch to Lilo.
    >>>
    >>> ... which won't work.
    >>>
    >>> -- Thomas Adam
    >>
    >> Thanks for pointing out the error of passing on unverified
    >> information vaguely remembered from diverse readings on the 'net.
    >>
    >>
    >> Kapil.
    >> --
    >
    > OK, I found more information about it. According to a user post in:
    > http://ubuntuforums.org/showthread.php?t=714798, it seems that RAID-1
    > as root filesystem works, whereas RAID-5 won't.
    >
    > I haven't tried it because I am away from the experimental machine, so
    > is there anyone who can confirm the above posting? Thanks in
    > advance...

Yes, that information still stands as being true.

-- Thomas Adam

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Mulyadi Santosa [mulyadi.santosa at gmail.com]

Sat, 5 Sep 2009 23:02:34 +0700

Hi...

On Sat, Sep 5, 2009 at 7:07 PM, Thomas Adam<thomas.adam22@gmail.com> wrote:

    > 2009/9/5 Mulyadi Santosa <mulyadi.santosa@gmail.com>:
    >> Hi everybody....
    >>
    >> On Sat, Sep 5, 2009 at 8:26 AM, Kapil Hari Paranjape<kapil@imsc.res.in> wrote:
    >>> Dear Thomas,
    >>>
    >>> On Sat, 05 Sep 2009, Thomas Adam wrote:
    >>>> 2009/9/5 Kapil Hari Paranjape <kapil@imsc.res.in>:
    >>>> > The other option is to switch to Lilo.
    >>>>
    >>>> ... which won't work.
    >>>
    >>> Thanks for pointing out the error of passing on unverified
    >>> information vaguely remembered from diverse readings on the 'net.
    >>>
    >>
    >> OK, I found more information about it. According to a user post in:
    >> http://ubuntuforums.org/showthread.php?t=714798, it seems that RAID-1
    >> as root filesystem works, whereas RAID-5 won't.
    >>
    >> I haven't tried it because I am away from the experimental machine, so
    >> is there anyone who can confirm the above posting? Thanks in
    >> advance...
    >
    > Yes, that information still stands as being true.

Thank you Thomas. I shall try it once I am back to the office and rework the installation. Probably the best approach in this case is put /boot partition as RAID-1 and the rest as RAID-5 (including swap).

    --
    regards,

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