Re: Re: [gentoo-user] /dev/sda* missing at boot

Re: Re: [gentoo-user] /dev/sda* missing at boot

[frares]

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Em 18/08/2011 16:13, Michael Mol <mikemol@gmail.com> escreveu:
> On Thu, Aug 18, 2011 at 2:59 PM, frares@gmail.com> wrote:
> >
> > Hi, guys
> >
> > It is a shame, I know, but after several years using Gentoo, it is the  
> first time I try to build a kernel without "genkernel".
> >
> > And now I can't boot to that new kernel, it does not find (and really  
> do not have a) /dev/sda* root partition ("real-root"); during the boot it  
> stops, complaining about that, gives me the option to get a shell, from  
> which I am able to see that there is no /dev/sda* .
> >
> > I have included everything SATA, so it looks like that is not a kernel  
> problem, but a initramfs issue, I guess.

> If you've got a SATA controller, no frills, then all you *really* need
> is AHCI. Build that into your kernel if you're worried about having
> the right modules in initramfs. You can break it out into a module
> later if you like. Opinions differ as to how much stuff should be
> broken into modules vs being built-in to the kernel. I tend to build
> in everything absolutely needed for boot, myself. Some people build in
> just about everything, and some people build in almost nothing.
> There's no "right" way for every use case.

> Also, check your BIOS to see if it's running your SATA controller in
> some kind of IDE emulation mode. If it is, disable that. (Some
> motherboards let you choose between "IDE" and "RAID", where "RAID" is
> AHCI mode. Others call IDE mode 'legacy', and still others might
> actually call the AHCI mode 'AHCI')

> Motherboards running SATA controllers in IDE emulation mode is an
> incredibly common thing:

> 17:18 beh
> 17:18 hda1 turned into sda1
> 17:19 IRule: Turn SCSI-generic support, or did you
> switch from legacy to AHCI in your BIOS?
> 17:20 shortcircuit: quiet, you

> --

> :wq


Thanks, gonna try it.

Francisco

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Re: Re: Re: [gentoo-user] /dev/sda* missing at boot

[frares]

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Em 18/08/2011 16:17, frares@gmail.com escreveu:
> Em 18/08/2011 16:13, Michael Mol mikemol@gmail.com> escreveu:
> > On Thu, Aug 18, 2011 at 2:59 PM, frares@gmail.com> wrote:
> > >
> > > Hi, guys
> > >
> > > It is a shame, I know, but after several years using Gentoo, it is  
> the first time I try to build a kernel without "genkernel".
> > >
> > > And now I can't boot to that new kernel, it does not find (and really  
> do not have a) /dev/sda* root partition ("real-root"); during the boot it  
> stops, complaining about that, gives me the option to get a shell, from  
> which I am able to see that there is no /dev/sda* .
> > >
> > > I have included everything SATA, so it looks like that is not a  
> kernel problem, but a initramfs issue, I guess.
> >
> > If you've got a SATA controller, no frills, then all you *really* need
> > is AHCI. Build that into your kernel if you're worried about having
> > the right modules in initramfs. You can break it out into a module
> > later if you like. Opinions differ as to how much stuff should be
> > broken into modules vs being built-in to the kernel. I tend to build
> > in everything absolutely needed for boot, myself. Some people build in
> > just about everything, and some people build in almost nothing.
> > There's no "right" way for every use case.
> >
> > Also, check your BIOS to see if it's running your SATA controller in
> > some kind of IDE emulation mode. If it is, disable that. (Some
> > motherboards let you choose between "IDE" and "RAID", where "RAID" is
> > AHCI mode. Others call IDE mode 'legacy', and still others might
> > actually call the AHCI mode 'AHCI')
> >
> > Motherboards running SATA controllers in IDE emulation mode is an
> > incredibly common thing:
> >
> > 17:18 beh
> > 17:18 hda1 turned into sda1
> > 17:19 IRule: Turn SCSI-generic support, or did you
> > switch from legacy to AHCI in your BIOS?
> > 17:20 shortcircuit: quiet, you
> >
> > --
> >
> > :wq
> >

> Thanks, gonna try it.

> Francisco

Forgot to say: I am able to boot the LiveCD and chroot to that partition.

Now checking the kernel configuration, there's only SATA_ACARD_AHCI set up  
as a module, everything else AHCI is included in the kernel.

Thanks anyway

Francisco

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Re: Re: Re: [gentoo-user] /dev/sda* missing at boot

[Michael Mol]

On Thu, Aug 18, 2011 at 3:26 PM,  <frares@gmail.com> wrote:
> Em 18/08/2011 16:17, frares@gmail.com escreveu:
>
> Forgot to say: I am able to boot the LiveCD and chroot to that partition.
>
> Now checking the kernel configuration, there's only SATA_ACARD_AHCI set up
> as a module, everything else AHCI is included in the kernel.

Don't forget to check your BIOS. You might also consider enabling
"SCSI-generic (disk)", which would catch ide-emulated disks and put a
scsi interface around them in the kernel. (That'd be an emulation
layer on top of an emulation layer, though, so far less than ideal)

Finally, check that it's coming up as "/dev/sda" and not something
like "/dev/sdb". The initial scrolling of kernel messages might tell
you what devices were detected and what names they were given.


-- 
:wq

Re: [gentoo-user] /dev/sda* missing at boot

[Peter Humphrey]

On Thursday 18 August 2011 20:42:30 Michael Mol wrote:

> Don't forget to check your BIOS. You might also consider enabling
> "SCSI-generic (disk)", which would catch ide-emulated disks and put a
> scsi interface around them in the kernel.

But it might well shove a generic driver in before the specific one has a 
chance. The docs warn of this.

> Finally, check that it's coming up as "/dev/sda" and not something
> like "/dev/sdb".

Good advice (if I may presume). BIOSes often have weird detection orders: 
I'm still not sure I've got the right optical drive order on my 
superannuated workstation.

-- 
Rgds
Peter		Linux Counter 5290, 1994-04-23