Last night I tried installing Ubuntu 9.10 along-side my default linux
install (Mepis). The install went fine, but Ubuntu overwrote my MBR.
Restoring the Mepis one worked fine, but now I can't chainload
ubuntu.

Ubuntu is on the /dev/sda7 partition and the grub entry I have is:

root (hd0,6)
chainloader +1

I forget the exact error (sorry, it was late), but it was something
along the lines of: error 13 invalid partition. Could this be a
Grub2 problem? Or, thinking about it, an ext4/Grub1 incompatibility?
TIA

-- 
The email address is a spam trap. I rarely use it.

"Chris"  wrote in message 
news:hd0rfn$dc6$1@news.eternal-september.org...
> Last night I tried installing Ubuntu 9.10 along-side my default linux
> install (Mepis). The install went fine, but Ubuntu overwrote my MBR.
> Restoring the Mepis one worked fine, but now I can't chainload
> ubuntu.
>
> Ubuntu is on the /dev/sda7 partition and the grub entry I have is:
>
> root (hd0,6)
> chainloader +1
>
> I forget the exact error (sorry, it was late), but it was something
> along the lines of: error 13 invalid partition. Could this be a
> Grub2 problem? Or, thinking about it, an ext4/Grub1 incompatibility?
> TIA
>

If it's grub2 then you should use root (hd0,7).

If it's grub1 then I don't think it will handle ext4 so updating to grub2 
(grub-pc) might be the answer.

-- 
Geoff

Geoffrey Clements wrote:

> "Chris"  wrote in message
> news:hd0rfn$dc6$1@news.eternal-september.org...
>> Last night I tried installing Ubuntu 9.10 along-side my default
>> linux install (Mepis). The install went fine, but Ubuntu overwrote
>> my MBR. Restoring the Mepis one worked fine, but now I can't
>> chainload ubuntu.
>>
>> Ubuntu is on the /dev/sda7 partition and the grub entry I have is:
>>
>> root (hd0,6)
>> chainloader +1
>>
>> I forget the exact error (sorry, it was late), but it was
>> something along the lines of: error 13 invalid partition. Could
>> this be a Grub2 problem? Or, thinking about it, an ext4/Grub1
>> incompatibility? TIA
>>
> 
> If it's grub2 then you should use root (hd0,7).

Why? Has it changed it's numbering scheme?

> If it's grub1 then I don't think it will handle ext4 so updating to
> grub2 (grub-pc) might be the answer.

Yeah, that's probably it. Any idea how painful/less that is? i.e. is
it just a drop-in replacement that will use my current grub menu.lst
file?

-- 
The email address is a spam trap. I rarely use it.

On Fri, 6 Nov 2009 11:31:58 -0000
"Geoffrey Clements"  wrote:

> If it's grub1 then I don't think it will handle ext4 so updating to grub2 
> (grub-pc) might be the answer.

I think it does handle ext4, because my root partition is ext4 and I'm
sticking with grub1 (grub-legacy). grub2 should still be consigned to
"experimental", it's nowhere near ready for mainstream distros yet IMO.

-- 
TH * http://www.realh.co.uk

On Fri, 06 Nov 2009 09:49:42 +0000, Chris wrote:

> Last night I tried installing Ubuntu 9.10 along-side my default linux
> install (Mepis). The install went fine, but Ubuntu overwrote my MBR.
> Restoring the Mepis one worked fine, but now I can't chainload ubuntu.
> 
> Ubuntu is on the /dev/sda7 partition and the grub entry I have is:
> 
> root (hd0,6)
> chainloader +1
> 
> I forget the exact error (sorry, it was late), but it was something along
> the lines of: error 13 invalid partition. Could this be a Grub2 problem?
> Or, thinking about it, an ext4/Grub1 incompatibility? TIA

If Ubuntu overwrote your MBR then presumably it installed its boot loader
there rather than onto the start of sda7. Did it ask about this?
Installers normally do.

If this is the case then there is no boot loader on sda7 to chain to. You
may need to use a rescue disc to install one.

You may also need "rootnoverify" rather than "root".

Regards, Ian

Ian Northeast wrote:

> On Fri, 06 Nov 2009 09:49:42 +0000, Chris wrote:
> 
>> Last night I tried installing Ubuntu 9.10 along-side my default
>> linux install (Mepis). The install went fine, but Ubuntu overwrote
>> my MBR. Restoring the Mepis one worked fine, but now I can't
>> chainload ubuntu.
>> 
>> Ubuntu is on the /dev/sda7 partition and the grub entry I have is:
>> 
>> root (hd0,6)
>> chainloader +1
>> 
>> I forget the exact error (sorry, it was late), but it was
>> something along the lines of: error 13 invalid partition. Could
>> this be a Grub2 problem? Or, thinking about it, an ext4/Grub1
>> incompatibility? TIA
> 
> If Ubuntu overwrote your MBR then presumably it installed its boot
> loader there rather than onto the start of sda7. Did it ask about
> this? Installers normally do.

Annoyingly, it didn't. I was expecting it would, which is annoying.
Also the default ubuntu boot screen is spectacularly dull.

> If this is the case then there is no boot loader on sda7 to chain
> to. You may need to use a rescue disc to install one.

Ah, of course! I'm not at all familiar with ubuntu, can I do it with
it's live CD?
 
> You may also need "rootnoverify" rather than "root".

I'll try that too, but I suspect it's the above.

Thanks Ian

-- 
The email address is a spam trap. I rarely use it.

Tony Houghton wrote:

> On Fri, 6 Nov 2009 11:31:58 -0000
> "Geoffrey Clements"  wrote:
> 
>> If it's grub1 then I don't think it will handle ext4 so updating
>> to grub2 (grub-pc) might be the answer.
> 
> I think it does handle ext4, because my root partition is ext4 and
> I'm sticking with grub1 (grub-legacy). grub2 should still be
> consigned to "experimental", it's nowhere near ready for mainstream
> distros yet IMO.

Judging from Ian's suggestion elsethread, I suspect the error is due
to there being no grub installed on /dev/sda7.

-- 
The email address is a spam trap. I rarely use it.

In article <hd122b$ptr$1@news.eternal-september.org>,
	Chris wrote:
> Geoffrey Clements wrote:

>> If it's grub1 then I don't think it will handle ext4 so updating to
>> grub2 (grub-pc) might be the answer.

> Yeah, that's probably it. Any idea how painful/less that is? i.e. is
> it just a drop-in replacement that will use my current grub menu.lst
> file?

No, it's not a drop-in replacement.

*** grub1 menu.lst extract ***

title           Debian GNU/Linux, kernel 2.6.31
root            (hd0,0)
kernel          /vmlinuz-2.6.31 root=/dev/sda5 blacklist=piix ro
initrd          /initrd.img-2.6.31

*** grub2 grub.cfg extract ***

menuentry "Debian GNU/Linux, with Linux 2.6.31" {
        insmod ext2
        set root=(hd0,1)
        linux   /vmlinuz-2.6.31 root=/dev/sda5 blacklist=piix ro
        initrd  /initrd.img-2.6.31
}

My /boot is on its own ext3 partition. grub1 numbers partitions from 0;
grub2 from 1.

-- 
Paul Martin

Paul Martin wrote:

> In article <hd122b$ptr$1@news.eternal-september.org>,
> Chris wrote:
>> Geoffrey Clements wrote:
> 
>>> If it's grub1 then I don't think it will handle ext4 so updating
>>> to grub2 (grub-pc) might be the answer.
> 
>> Yeah, that's probably it. Any idea how painful/less that is? i.e.
>> is it just a drop-in replacement that will use my current grub
>> menu.lst file?
> 
> No, it's not a drop-in replacement.

Shame. I guess it's to be expected from the large version increment.

> *** grub1 menu.lst extract ***
> 
> title           Debian GNU/Linux, kernel 2.6.31
> root            (hd0,0)
> kernel          /vmlinuz-2.6.31 root=/dev/sda5 blacklist=piix ro
> initrd          /initrd.img-2.6.31
> 
> *** grub2 grub.cfg extract ***
> 
> menuentry "Debian GNU/Linux, with Linux 2.6.31" {
>         insmod ext2
>         set root=(hd0,1)
>         linux   /vmlinuz-2.6.31 root=/dev/sda5 blacklist=piix ro
>         initrd  /initrd.img-2.6.31
> }
> 
> My /boot is on its own ext3 partition. grub1 numbers partitions
> from 0; grub2 from 1.

How confusing is that?! It looks like it still numbers disks from 0.
If they were going to change numbers to start from 1, why not do it
across the board?

-- 
The email address is a spam trap. I rarely use it.

On Fri, 06 Nov 2009 13:46:44 +0000, Chris wrote:

> Ian Northeast wrote:

>> If Ubuntu overwrote your MBR then presumably it installed its boot
>> loader there rather than onto the start of sda7. Did it ask about this?
>> Installers normally do.
> 
> Annoyingly, it didn't. I was expecting it would, which is annoying. Also
> the default ubuntu boot screen is spectacularly dull.
> 
>> If this is the case then there is no boot loader on sda7 to chain to.
>> You may need to use a rescue disc to install one.
> 
> Ah, of course! I'm not at all familiar with ubuntu, can I do it with it's
> live CD?

I don't know Ubuntu either, but I'd be very surprised if you couldn't,
it's one of the commonest tasks a boot CD is needed for. You may have to
mount your Ubuntu root filesystem somewhere and chroot to it before
running grub-install (specifying the partition as the boot loader
location).

>> You may also need "rootnoverify" rather than "root".
> 
> I'll try that too, but I suspect it's the above.

I don't think this is as likely either. The docs aren't very clear as to
when this is required.

Regards, Ian

Chris wrote:

> Geoffrey Clements wrote:
> 
>> "Chris"  wrote in message
>> news:hd0rfn$dc6$1@news.eternal-september.org...
>>> Last night I tried installing Ubuntu 9.10 along-side my default
>>> linux install (Mepis). The install went fine, but Ubuntu overwrote
>>> my MBR. Restoring the Mepis one worked fine, but now I can't
>>> chainload ubuntu.
>>>
>>> Ubuntu is on the /dev/sda7 partition and the grub entry I have is:
>>>
>>> root (hd0,6)
>>> chainloader +1
>>>
>>> I forget the exact error (sorry, it was late), but it was
>>> something along the lines of: error 13 invalid partition. Could
>>> this be a Grub2 problem? Or, thinking about it, an ext4/Grub1
>>> incompatibility? TIA
>>>
>> 
>> If it's grub2 then you should use root (hd0,7).
> 
> Why?

Yes, partitions are numbered from 1 not 0.

> Has it changed it's numbering scheme?
> 
>> If it's grub1 then I don't think it will handle ext4 so updating to
>> grub2 (grub-pc) might be the answer.
> 
> Yeah, that's probably it. Any idea how painful/less that is? i.e. is
> it just a drop-in replacement that will use my current grub menu.lst
> file?
> 

Other posters think grub1 can do ext4, I just don't know. In any case, using 
Debian Testing I switched from grub1 to grub2 quite a while back. It was 
very easy, even allowing you to test the grub2 bootloader by chainloading it 
from the original grub1 loader first thereby allowing you to roll-back if it 
doesn't work. Since then things have worked fine but it's worth brushing up 
on the differences, the config is done in a completely different way.

In the end the only difference (for me) is that grub2 is under active 
development so you get more updates than for grub1.

-- 
Geoff

In article <hd1jrq$gtv$1@news.eternal-september.org>,
	Geoff Clements wrote:

> Other posters think grub1 can do ext4, I just don't know.

It doesn't matter if you have a separate /boot partition.

-- 
Paul Martin

On 06/11/2009 16:37, Ian Northeast wrote:
> On Fri, 06 Nov 2009 13:46:44 +0000, Chris wrote:
>
>> Ian Northeast wrote:
>
>>> If Ubuntu overwrote your MBR then presumably it installed its boot
>>> loader there rather than onto the start of sda7. Did it ask about this?
>>> Installers normally do.
>>
>> Annoyingly, it didn't. I was expecting it would, which is annoying. Also
>> the default ubuntu boot screen is spectacularly dull.
>>
>>> If this is the case then there is no boot loader on sda7 to chain to.
>>> You may need to use a rescue disc to install one.
>>
>> Ah, of course! I'm not at all familiar with ubuntu, can I do it with it's
>> live CD?
>
> I don't know Ubuntu either, but I'd be very surprised if you couldn't,
> it's one of the commonest tasks a boot CD is needed for. You may have to
> mount your Ubuntu root filesystem somewhere and chroot to it before
> running grub-install (specifying the partition as the boot loader
> location).
>
>>> You may also need "rootnoverify" rather than "root".
>>
>> I'll try that too, but I suspect it's the above.

For various reasons I needed to re-install Ubuntu anyway, so I found the 
option to install grub in its own partition rather than MBR. It was 
under a small 'Advanced' button. A quick edit of my usual grub menu.lst 
and Ubuntu is being chainloaded fine by grub 1.

Thanks to all for help.

Geoff Clements wrote:

> Chris wrote:
> 
>> Geoffrey Clements wrote:
>> 
>>> "Chris"  wrote in message
>>> news:hd0rfn$dc6$1@news.eternal-september.org...
>>>> Last night I tried installing Ubuntu 9.10 along-side my default
>>>> linux install (Mepis). The install went fine, but Ubuntu
>>>> overwrote my MBR. Restoring the Mepis one worked fine, but now I
>>>> can't chainload ubuntu.
>>>>
>>>> Ubuntu is on the /dev/sda7 partition and the grub entry I have
>>>> is:
>>>>
>>>> root (hd0,6)
>>>> chainloader +1
>>>>
>>>> I forget the exact error (sorry, it was late), but it was
>>>> something along the lines of: error 13 invalid partition. Could
>>>> this be a Grub2 problem? Or, thinking about it, an ext4/Grub1
>>>> incompatibility? TIA
>>>>
>>> 
>>> If it's grub2 then you should use root (hd0,7).
>> 
>> Why?
> 
> Yes, partitions are numbered from 1 not 0.

But not disks? That seems confusing.

-- 
The email address is a spam trap. I rarely use it.

"Chris"  wrote in message 
news:hd8lgb$873$1@news.eternal-september.org...
> Geoff Clements wrote:
>
>> Chris wrote:
>>
>>> Geoffrey Clements wrote:
>>>
>>>> "Chris"  wrote in message
>>>> news:hd0rfn$dc6$1@news.eternal-september.org...
>>>>> Last night I tried installing Ubuntu 9.10 along-side my default
>>>>> linux install (Mepis). The install went fine, but Ubuntu
>>>>> overwrote my MBR. Restoring the Mepis one worked fine, but now I
>>>>> can't chainload ubuntu.
>>>>>
>>>>> Ubuntu is on the /dev/sda7 partition and the grub entry I have
>>>>> is:
>>>>>
>>>>> root (hd0,6)
>>>>> chainloader +1
>>>>>
>>>>> I forget the exact error (sorry, it was late), but it was
>>>>> something along the lines of: error 13 invalid partition. Could
>>>>> this be a Grub2 problem? Or, thinking about it, an ext4/Grub1
>>>>> incompatibility? TIA
>>>>>
>>>>
>>>> If it's grub2 then you should use root (hd0,7).
>>>
>>> Why?
>>
>> Yes, partitions are numbered from 1 not 0.
>
> But not disks? That seems confusing.
>

Yeah - I had to double check that, there's nothing that I could find that 
said that disk numbering had changed but there was a paragraph that said 
that partition numbering had changed.

I suppose it makes sense in that it's a closer match to the linux scheme, 
i.e hda4 becomes (hd0, 4) so no more off-by-one errors (unless you happen to 
be an ex-grub1 user) but if it were me I'd have just changed to the linux 
scheme completely, I know grub boots more than linux but it must be the most 
often booted OS by grub.

-- 
Geoff