# [SOLVED] Cannot boot after kernel upgrade

## cessman4life

[/b]I recently upgraded to 2.6.19-gentoo-r1 but cannot boot into the system. (fortunately i keep an old failsafe configuration while upgrading). I think the prime suspect is the sata configuration in the kernel. in previous kernels there was an option in [scsi low-level drivers] to enable [promise sata TX2/TX4 support]. this option however is no longer available. is there a workaround for this? and yes, i do have a sata hard drive.Last edited by cessman4life on Tue Dec 19, 2006 1:38 pm; edited 2 times in total

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## Raistlin

 *cessman4life wrote:*   

> I recently upgraded to 2.6.19-gentoo-r1 but cabbot boot into the system. 

 

Please be more specific: What is the error message? Kernel panic? ANY information helps, because the way you've described right now would even allow somebody to ask whether the computer is plugged in to the power cord correctly  :Wink: 

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## whig

For 2.6.19, we all had to re-enable SATA support in the kernel, eg in menuconfig. A change or re-arrangement deselected the old settings brought over by running oldconfig.

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## cessman4life

I'm sorry. One of my favorite movies was on so I rushed a bit. The error message indicated that /dev/sda4 is not a valid root device then it asks me to specify the location of root. This is immediately after the modules have been loaded. I know that /dev/sda4 is fine because all devices are the same for both the failsafe and the new configuration. As a matter of fact I also loaded the old config from the failsafe kernel, ie, /usr/src/linux-2.6.18-gentoo-r1/.config.

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## didymos

Well, one oddity of the new setup is that even with the SATA modules built and loaded, you still have to enable SCSI disk support or the disk is inaccessible.  Why you'd want SATA without the ability to actually do anything with it, I don't know.

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## whig

A 2.6.18 failsafe kernel should be fine. A 2.6.19 kernel with a 2.6.18 .config won't work.

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## cessman4life

Using an old .config worked with previous kernel versions. Why should it not work with this new kernel? What has changed so drastically between 2.6.18 and 2.6.19?

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## didymos

Well, for one thing, all the SATA stuff got moved out of the SCSI config. But, like I said, it still requires SCSI disk support to be enabled.  I haven't looked at what the config system is doing differently, so who knows what it defaults to when you try to use an old config.

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## Enlight

oldconfig will work if you answer yes to ATA support, but at first thought, most people wondered, hey my sata disk are under scsi and it's advised to use old IDE config for ide drives and not libata one, so we answered no and got screwed.

edit : as for the scsi support still being needed, I'll check when i'll be home, but I'm quite sure that it's not needed anymore.

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## cessman4life

I found what I was looking for. I'm recompiling the kernel and apparently the 'Promise Sata TX2/TX4 Support' was moved from SCSI Low-level Drivers to 'Serial ATA (prod) and Parallel ATA (experimental) drivers' under Device Drivers. I will let you know if the new compilation was a success.   :Very Happy: 

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## cessman4life

Well the problem still exists so now I'm stumped.

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## didymos

Oh, it's needed.  I ran into this when I disabled SCSI thinking libata would do the trick. No.  So, I enabled SCSI, then disk support, built it as a module, and loaded.  Magically, my SATA drive appears in /dev.  So I recompiled the kernel with scsi+disk support inbuilt, and did a little searching while I waited.  I can't recall the URL, but I found a couple different mailing lists where this had happened to people. I actually think there was something about this on the LKML.

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## at

I had the same problem when upgrading from linux-2.6.18-hardened to linux-2.6.19-hardened kernel.

To solve it, I had to enable

```

Device Drivers  --->

   Serial ATA (prod) and Parallel ATA (experimental) drivers  --->

      <*>  ATA device support

      <*>  NVIDIA SATA support

```

But you would probably have to select a different driver.

I hope it helps.

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## cessman4life

That's what I tried after I found out the SCSI options were moved. No luck still.

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## Boris Kavod

Same problem here  :Sad: 

From:

```

Device Drivers  --->

 SCSI device support  --->

  SCSI low-level drivers  --->

   <*> Serial ATA (SATA) support

   <*>   Intel PIIX/ICH SATA support

```

To:

```

Device Drivers  --->

 Serial ATA (prod) and Parallel ATA (experimental) drivers  --->

  <*> ATA device support

  <*>   Intel PIIX/ICH SATA support

```

Error message at boot:

```

Kernel panic - not syncing: VFS: Unable to mount root fs on unknow-block(0,0) 

```

(and sometime unknow-block(8,2) ????)

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## Jimmers

I had this problem, and I fixed it by setting my SATA drives to be detected as AHCI instead of IDE in the kernel (2.6.18-r3)

EDIT:  Sorry, I ment that I had the drives detected as AHCI in the BIOS

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## cessman4life

Thanks Jimmers. I switched from IDE to RAID in the BIOS and now all is well.

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