[gentoo-user] root fs moved, but no init

[gentoo-user] root fs moved, but no init

[Adam Carter]

Summary;
Copied / from sda3 to sdb3
Updated the fstab in the new disk (/dev/sdb3       /
btrfs           noatime,compress=lzo    0 0)
Updated the kernel line's root=/dev/sda3 to /dev/sdb3 in grub.conf,
but left the root (hd0,0) as it is. So, kernel is loaded from sda but
init should run from sdb.
When booting the kernel successfully mounts /dev/sdb3 as root fs
Then the system halts at one of the freeing memory messages, but I
assume the problem is that init isn't executed from /dev/sdb3

Since root is mounted, i know i have all the drivers I need in the
kernel. Any ideas why booting stops?

[gentoo-user] Re: root fs moved, but no init

[walt]

On 07/23/2011 04:49 PM, Adam Carter wrote:
> Summary;
> Copied / from sda3 to sdb3
> Updated the fstab in the new disk (/dev/sdb3       /
> btrfs           noatime,compress=lzo    0 0)
> Updated the kernel line's root=/dev/sda3 to /dev/sdb3 in grub.conf,
> but left the root (hd0,0) as it is. So, kernel is loaded from sda but
> init should run from sdb.
> When booting the kernel successfully mounts /dev/sdb3 as root fs
> Then the system halts at one of the freeing memory messages, but I
> assume the problem is that init isn't executed from /dev/sdb3
> 
> Since root is mounted, i know i have all the drivers I need in the
> kernel. Any ideas why booting stops?

Are the perms correct on the copied init?

[gentoo-user] Re: root fs moved, but no init

[Nicolas Sebrecht]

On Sun, Jul 24, 2011 at 09:49:21AM +1000, Adam Carter wrote:
> Summary;
> Copied / from sda3 to sdb3
> Updated the fstab in the new disk (/dev/sdb3       /
> btrfs           noatime,compress=lzo    0 0)
> Updated the kernel line's root=/dev/sda3 to /dev/sdb3 in grub.conf,
> but left the root (hd0,0) as it is. So, kernel is loaded from sda but
> init should run from sdb.
> When booting the kernel successfully mounts /dev/sdb3 as root fs
> Then the system halts at one of the freeing memory messages, but I
> assume the problem is that init isn't executed from /dev/sdb3
> 
> Since root is mounted, i know i have all the drivers I need in the
> kernel. Any ideas why booting stops?

Unix rights on files? How did you copy the system?

-- 
Nicolas Sebrecht

Re: [gentoo-user] Re: root fs moved, but no init

[Adam Carter]

> Unix rights on files? How did you copy the system?

Yep, identical to the original. I used tar to copy the files and
maintain permissions. Checksums match too.

Re: [gentoo-user] root fs moved, but no init

[Neil Bothwick]

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On Sun, 24 Jul 2011 09:49:21 +1000, Adam Carter wrote:

> When booting the kernel successfully mounts /dev/sdb3 as root fs
> Then the system halts at one of the freeing memory messages, but I
> assume the problem is that init isn't executed from /dev/sdb3

Doesn't the kernel say something along the lines of "unable to run" init"
when it can't find it. You can test whether it is getting as far as
trying to run init by adding "init=/bin/sh" to your kernel options, which
should drop you straight into a shell.


-- 
Neil Bothwick

"Two things are infinite: the universe and human stupidity;
 and I'm not sure about the the universe."
 (Albert Einstein)

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Re: [gentoo-user] root fs moved, but no init

[Albert Hopkins]

On Sunday, July 24 at 09:49 (+1000), Adam Carter said:

> Summary;
> Copied / from sda3 to sdb3
> Updated the fstab in the new disk (/dev/sdb3       /
> btrfs           noatime,compress=lzo    0 0)
> Updated the kernel line's root=/dev/sda3 to /dev/sdb3 in grub.conf,
> but left the root (hd0,0) as it is. So, kernel is loaded from sda but
> init should run from sdb.
> When booting the kernel successfully mounts /dev/sdb3 as root fs
> Then the system halts at one of the freeing memory messages, but I
> assume the problem is that init isn't executed from /dev/sdb3

I wouldn't assume.  If init isn't executed you should get an explicit
error from the kernel:

        Kernel panic - not syncing: No init found. Try passing init=
        option to the kernel.

Re: [gentoo-user] root fs moved, but no init

[Adam Carter]

On Mon, Jul 25, 2011 at 5:57 PM, Neil Bothwick <neil@digimed.co.uk> wrote:
> On Sun, 24 Jul 2011 09:49:21 +1000, Adam Carter wrote:
>
>> When booting the kernel successfully mounts /dev/sdb3 as root fs
>> Then the system halts at one of the freeing memory messages, but I
>> assume the problem is that init isn't executed from /dev/sdb3
>
> Doesn't the kernel say something along the lines of "unable to run" init"
> when it can't find it. You can test whether it is getting as far as
> trying to run init by adding "init=/bin/sh" to your kernel options, which
> should drop you straight into a shell.

No message about init, just no more console messages. I'll try the
kernel line. Thanks.

Re: [gentoo-user] root fs moved, but no init

[Adam Carter]

> No message about init, just no more console messages. I'll try the
> kernel line. Thanks.

Ok. i ran init from the shell, and it reported /dev/initctl no such
device or directory.

I hadnt copied the contents of /dev across - i thought it was created
automagically?

Anyway, its copied now and I have booted successfully from the sdb.

Thanks Neil and Albert!

Re: [gentoo-user] root fs moved, but no init

[Albert Hopkins]

On Monday, July 25 at 21:04 (+1000), Adam Carter said:

> > No message about init, just no more console messages. I'll try the
> > kernel line. Thanks.
> 
> Ok. i ran init from the shell, and it reported /dev/initctl no such
> device or directory.
> 
> I hadnt copied the contents of /dev across - i thought it was created
> automagically?
> 
> Anyway, its copied now and I have booted successfully from the sdb.

There is always (well usually)* an initial /dev created in root.  This is needed
for before udev kicks in.  You should always copy that (and make sure it's /dev on
the root fs, not the udev /dev that gets mounted over it.

* This was the cause of a bug in the stage3 tarballs a few weeks back, where some /dev
entries did not exist in the tarball and the result was that people were able to 
successfully install Gentoo, but were not able to successfully boot into the
installation.