# no root mount with hybrid 'diskless' boot [SOLVED]

## mounty1

Hello, I'm using a diskless workstation (HP t5745) which has 2 GiB of local flash storage set to look like an IDE hard drive to the software.  I've followed the instructions in http://www.gentoo.org/doc/en/diskless-howto.xml on setting up a diskless boot, where the root file system is on a Solaris NFS server and the kernel is on the flash 'HDD'.  This is a crucial difference from the scenario described in the guide:  the kernel is stored locally, avoiding the need for bootparams, PXE etc.

The kernel works fine when running with an attached USB hard-drive, albeit too slowly, which is the motivation for going to the NFS root.  The kernel has all options for booting from both USB-attached storage and (I think/hope) from NFS servers.  The USB system sets eth0 to 192.168.1.58, as per the NFS boot.

The grub.conf menu has three options:small Gentoo system held on the flash HDD with overspill onto some USB memory sticks (another kernel).Working USB rootNon-working NFS rootWhen the NFS-root configuration is booted, it halts with a kernel panic, unable to mount root.  I can mount the root file system when the USB root kernel has booted.

```
default 1

timeout 7

splashimage=(hd0,0)/boot/grub/splash.xpm.gz

title Gentoo Linux

root (hd0,0)

kernel /boot/vmlinuz-2.6.37-gentoo-r1 root=/dev/sda1 quiet video=card0-LVDS-1:d

title Gentoo Linux 2.6.28-r2

root (hd0,0)

kernel /boot/vmlinuz-2.6.38-tuxonice-r2 rootdelay=10 root=/dev/sdc2 swap=/dev/sdc5 resume=swap:/dev/sdc5 rootfstype=ext4 video=card0-LVDS-1:d quiet

title Gentoo Dickless

root (hd0,0)

kernel /boot/vmlinuz-2.6.38-tuxonice-r2 swap=/dev/sdc5 resume=swap:/dev/sdc5 video=card0-LVDS-1:d ip=192.168.1.58 root=/dev/nfs nfsroot=192.168.1.1:/dickless/dickless

# vim:ft=conf:
```

Kernel configuration is at http://pastebin.com/n8KgTWz6

Any idea why the kernel won't perform the root mount ?

----------

## solamour

Here is a configuration that worked for me. The difference is that in my case, the kernel itself is loaded from the tftp server, but I think that would make little difference.

```
Boot Menu

====================

diskless

gentoo      2011.08

gentoo64    2011.09

...

```

```
display bootmenu.txt

default diskless

prompt 1

timeout 0

label diskless

   kernel diskless/boot/kernel-2.6.39-gentoo-r3

   append ip=dhcp root=/dev/nfs nfsroot=192.168.0.254:/var/tftp/diskless

...

```

```
...

dhcp-boot=pxelinux.0

enable-tftp

tftp-root=/var/tftp

tftp-port-range=2070,2071

```

```
/var/tftp/diskless *(rw,sync,no_root_squash,no_subtree_check)

```

I have the whole Gentoo installed in the tftp server's "/var/tftp/diskless" directory. Other than the usual nfs and network interface related options in the kernel, there wasn't anything particularly unusual.

I referred the following links.

http://www.gentoo.org/doc/en/diskless-howto.xml

http://www.gentoo-wiki.info/HOWTO_Gentoo_Diskless_Install

__

solLast edited by solamour on Thu Sep 15, 2011 4:40 pm; edited 1 time in total

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## mounty1

... now experts who might actually be able to answer, who see the question replied-to, might not bother to read it.

Know this:  if you have nothing to say, it's better to say nothing.

Thanks very much indeed.

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## Jaglover

Are you following some howto? I never tried such a setup myself, looking at your Grub entry I tried to figure out how it would work without udev, etc. Then I found a guide here http://www.ibiblio.org/pub/Linux/docs/HOWTO/other-formats/html_single/NFS-Root-Client-mini-HOWTO.html

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## mounty1

 *Jaglover wrote:*   

> Are you following some howto?

 I did say so, and quoted the URL in the original posting. *Jaglover wrote:*   

> I never tried such a setup myself, looking at your Grub entry I tried to figure out how it would work without udev, etc. Then I found a guide here http://www.ibiblio.org/pub/Linux/docs/HOWTO/other-formats/html_single/NFS-Root-Client-mini-HOWTO.html

 That guide is hopelessly incomplete and twelve years old.

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## lgringo

Hi,

In fact, everything was fine for me with kernel 2.6.36-gentoo-r5.

I've just switched to 2.6.39-gentoo-r3 and it does not boot (same problem : VFS : Unable to mount root fs via NFS, trying floppy ... )

So try with an older kernel ...

Meanwhile I'm looking for a solution with 2.6.39

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## mounty1

 *lgringo wrote:*   

> Hi, [...] I've just switched to 2.6.39-gentoo-r3 and it does not boot (same problem : VFS : Unable to mount root fs via NFS, trying floppy ... ) [...]

 It's working here for me with 3.0.6;  can you try that ?   Try the boot nfsrootdebug parameter.

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## lgringo

Hi,

I've found my issue. Some options were added that are not NFS options but standard mount options :

APPEND ip=dhcp root=/dev/nfs rw nfsroot=10.10.11.152:/diskless/actuel,noatime,nolock,intr nfsrootdebug

Using nfsrootdebug show me 2 errors :

  -> unrecognized mount option 'noatime'

  -> ignoring mount option 'intr'

In fact, if there is one unrecognized option, the boot failed.

I do not know if someone change the options and did not try them, or if new kernel is less lenient.

----------

