Syslinux - Jun 2002 - VFS: Cannot open root device, pxelinux nfsroot

Hi everyone,

I got the error:

NET4: Unix domain sockets 1.0/smp for linux NET4.0
ds: no socket drivers loaded
request_module[block-major-8]: root fs not mounted
VFS: Cannot open root device ""or 08:03
Please append a correct "root"boot option

The strange thing is that it tries to mount from harddisk. This I got somewhere
else:
 "the kernel looks like it is trying to boot off of 08:03, which is
correct, /dev/sda3."
sda3 is indeed the root partition of the scsi harddisk.

It seems the kernel tries to mount /dev/sda3 as root instead of mounting the
directory offered by nfsserver.

VFS: Cannot open root device ""or 08:03 
Please append a correct "root"boot option 
So it does't even mention to try mounting with nfs protocol. 

Getting kernel goes ok, so there seems to be some misunderstanding between
pxelinux config file and nfsserver.
These are my config files:

/tftpboot/pxelinux.cfg/default I got:
LABEL  linux
KERNEL  bzImage
APPEND root=/dev/nfs ip=dhcp nfsroot=192.168.1.1:/netboot/base

/etc/exports:
/netboot/base       192.168.1.0/255.255.255.0(rw,no_root_squash)

/etc/hosts.allow:
ALL:ALL

/etc/hosts.deny:
 is empty

rpcinfo -p : says portmapper, mountd and nfs are active.

My log that logs all says nothing after DHCPPACK for ip assignment by dhcpd and
"tftp: client does not accept options" which is normal I understand.

I have also tried to use other kernels and root filesystems (in /netboot/base,
client was supposed to nfs) but without succes.
The kernels I made all gave the error:

NET4: Unix domain sockets 1.0/smp for linux NET4.0
ds: no socket drivers loaded
request_module[block-major-8]: root fs not mounted
VFS: Cannot open root device ""or 08:03
Please append a correct "root"boot option

And a kernel I ripped of a bootflop gave not the error:
ds: no socket drivers loaded
but has propably not the necessary modules for nfsroot compiled.

I am at a loss, I have no idee why it's not working.
If anyone has a sugestion I would very much apreciate it.
If anyone who uses pxelinux in combination with nfsroot, could say if at least
the config files are ok would be very helpfull as well.


Rob

Hi,

<rob.vogel at hetnet.nl> schrieb am 12.06.02
13:24:51:
> Hi everyone,
> 
> I got the error:
> 
> NET4: Unix domain sockets 1.0/smp for linux NET4.0
> ds: no socket drivers loaded
> request_module[block-major-8]: root fs not mounted
> VFS: Cannot open root device ""or 08:03
> Please append a correct "root"boot option
usually you should see something like
IP-Config [dhcp answer]               
NET4:[..]
Looking up port of RPC 10003/2 on [server IP]
Looking up port of RPC 10005/1 on [server IP]
VFS: Mounted root (nfs filesystem)

Are you sure you have nfsroot in the kernel? Does the client get some IP address
in the kernel? Is the network card in the kernel (*fixed, not as a module!*)?
> /tftpboot/pxelinux.cfg/default I got:
> LABEL  linux
> KERNEL  bzImage
> APPEND root=/dev/nfs ip=dhcp nfsroot=192.168.1.1:/netboot/base
looks correct, you could also leave out the 'root=/dev/nfs'.

Regards,

Josef

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On Wed, Jun 12, 2002 at 01:17:23PM +0200, rob.vogel at hetnet.nl
wrote:
> Hi everyone,
hey,
> I got the error:
oh, that's not good :)

> /tftpboot/pxelinux.cfg/default I got:
> LABEL  linux
> KERNEL  bzImage
> APPEND root=/dev/nfs ip=dhcp nfsroot=192.168.1.1:/netboot/base
you can leave the root=/dev/nfs here. In stead, do this:

on the machine where you are compiling the kernel, make /dev/nfs:
  mknod /dev/nfs c 0 255

and then use rdev to make your kernel point to it:
  rdev <kernelimage> /dev/nfs

You probably already did all this, because you read the
Diskless-root-NFS-HOWTO
(http://www.tldp.org/HOWTO/Diskless-root-NFS-HOWTO.html), but I'm just
making
sure here :)

grtz, Tijn

-- 
 2:08PM  up 51 days, 16:08, 5 users, load averages: 0.00, 0.02, 0.03

Hi,

Martijn Bakker <martijn-syslinux at insecure.nl> schrieb am 12.06.02
14:26:39:
> you can leave the root=/dev/nfs here. In stead, do this:
[rdev usage deleted]

you don't want to use rdev.

Regards,

Josef

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(oops, tried to send to zytor.org :)

On Wed, Jun 12, 2002 at 07:52:35PM +0200, Josef Siemes
wrote:
> you don't want to use rdev.
why not? (just curious, since I almost copy/paste'd this from the NFSROOT
HOWTO).

grtz, Tijn

-- 
 8:13PM  up 51 days, 22:13, 4 users, load averages: 0.08, 0.11, 0.05

Thank's Josef and Martijn,

>usually you should see something like
>IP-Config [dhcp answer]               
>NET4:[..]
>Looking up port of RPC 10003/2 on [server IP]
>Looking up port of RPC 10005/1 on [server IP]
>VFS: Mounted root (nfs filesystem)
I don't see that, but there are no errors about portmap or rpc either.
rpcinfo finds portmapper, mountd, nfs runnig.
>Are you sure you have nfsroot in the kernel? Does the client get some IP
address
>in the kernel? Is the network card in the kernel (*fixed, not as a
module!*)?
Yes, I got Networking Options:
TCP/IP networking (CONFIG_INET), IP: kernel level autoconfiguration
(CONFIG_IP_PNP),
IP: DHCP support (CONFIG_IP_PNP_DHCP)
File Systems:
/dev file system support (CONFIG_DEVFS_FS), Automatically mount at boot
(CONFIG_DEVFS_MOUNT)
Network File Systems:
NFS file system support (CONFIG_NFS_FS), Root file system on NFS
(CONFIG_ROOT_NFS)
So that should cover it all.
> on the machine where you are compiling the kernel, make /dev/nfs:
> mknod /dev/nfs c 0 255
> rdev <kernelimage> /dev/nfs
I did this ( I saw later it is not required, but) and now I get a differen
error:

	Sim 710: no NCR53C710 adapter found
	request_module[scsi_hostadapter]: root fs not mounted
	NET4: linux TCP/IP 1.0 for NET4.0
	IP Protocols: ICMP,UDP,TCP,IGMP
	IP: Routing cache bash table of 2048 buckets, 16Kbytes
	TCP: Hash tables configured 
	NET4: Unix domain sockets 1.0/SMP for linux NET4.0
	Root-NFS: no nfs server available, giving up
	VFS: Unable to mount fs via NFS, trying floppy

At least it tries to mount via NFS, but now it sees no NFS daemon?
portmap, rpc.nfsd are running. rpcinfo -p netserver sees portmap,mountd and nfs.
Ifconfig sees eth0 with 192.168.1.1 
>> you don't want to use rdev.
> why not? (just curious, since I almost copy/paste'd this from the
NFSROOT
> HOWTO).
I think 'rdev <kernelimage> /dev/nfs' is only used as default, if
you don't override it with the kernel option:
	'nfsroot=<ip-address>:</root/path>' 
it uses a default path, with rdev you override this option (and more if you
wish). So it should be possible to leave 'root=/dev/nfs' out and use
rdev instead.

/tftpboot/pxelinux.cfg/default I got:
LABEL  linux
KERNEL  bzImage
APPEND root=/dev/nfs ip=dhcp nfsroot=192.168.1.1:/netboot/base

I know nothing about tcpdump, but maybe who does can see something in it?
With tcpdump I get the following:

netserver:~ # tcpdump -ql > dat & tail -f dat[5] 
1)---------
1644tcpdump: listening on eth0 16:53:36.766368 0.0.0.0.bootpc >
255.255.255.255.bootps:  udp 548 16:53:36.766982 netserver.bootps >
255.255.255.255.bootpc:  udp 322 [tos 0x10] 16:53:36.766368 0.0.0.0.bootpc >
255.255.255.255.bootps:  xid:0x8ca0735a secs:1024 flags:0x8000 [|bootp]
2)---After this it says the following a few hundred times-- 
16:51:12.054549 netserver.32771 > 192.168.1.149.56074:  udp 516
(DF)16:51:12.054999 192.168.1.149.56074 > netserver.32771:  udp 4
arp who-has 192.168.
3)-------As last it says:
arp who-has 192.168.1.149 tell netserver

I hope someone can actually read this.
I don't have arp and bootp configured in the kernel, since I don't need
it for nfs mount, right?

Anyone got a clue?
Thanks,

Rob

Hi,

Martijn Bakker <martijn at insecure.nl> schrieb am 12.06.02
20:22:16:
> On Wed, Jun 12, 2002 at 07:52:35PM +0200, Josef Siemes wrote:
> > you don't want to use rdev.
> 
> why not? (just curious, since I almost copy/paste'd this from the
NFSROOT
> HOWTO).
look at the manpage for rdev: 'The rdev utility [..] is an ancient hack
[..].
[..] Use a bootloader like SysLinux or LILO instead'.

And sure it is a hack, since 
- this isn't usable on non-x86 systems.
- You may get problems with devfs, since this has no fixed major/minor for
some device, and rdev only puts just this major/minor into the kernel - not
the device name.
- it is just another way to specify the root device - there are already enough.
- (to be continued ...)

It is a tool from the very beginning of the linux kernel (pre-1.0), when 
there was no syslinux, lilo or else available as a bootloader.

Regards,

Josef
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All inclusive! 100 MB Speicher, SMS 50% gunstiger, 32 MB Attachment-Gro?e, 
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Hi,

<rob.vogel at hetnet.nl> schrieb am 13.06.02
11:12:02:
> I don't see that, but there are no errors about portmap or rpc either.
Then the kernel doesn't use nfsroot - either because it isn't compiled
in,
or there's another reason for this.
> >Are you sure you have nfsroot in the kernel? Does the client get some
IP address
> >in the kernel? Is the network card in the kernel (*fixed, not as a
module!*)?
> Yes, I got Networking Options:
> TCP/IP networking (CONFIG_INET), IP: kernel level autoconfiguration
(CONFIG_IP_PNP),
> IP: DHCP support (CONFIG_IP_PNP_DHCP)
> File Systems:
> /dev file system support (CONFIG_DEVFS_FS), Automatically mount at boot
(CONFIG_DEVFS_MOUNT)
> Network File Systems:
> NFS file system support (CONFIG_NFS_FS), Root file system on NFS
(CONFIG_ROOT_NFS)
> So that should cover it all.
Is the device driver in the kernel? Does it do IP Autoconfig? What does it tell
you?
> 
> > on the machine where you are compiling the kernel, make /dev/nfs:
> > mknod /dev/nfs c 0 255
> > rdev <kernelimage> /dev/nfs
> 
> I did this ( I saw later it is not required, but) and now I get a differen
error:
> 
> 	Sim 710: no NCR53C710 adapter found
> 	request_module[scsi_hostadapter]: root fs not mounted
> 	NET4: linux TCP/IP 1.0 for NET4.0
> 	IP Protocols: ICMP,UDP,TCP,IGMP
> 	IP: Routing cache bash table of 2048 buckets, 16Kbytes
> 	TCP: Hash tables configured 
> 	NET4: Unix domain sockets 1.0/SMP for linux NET4.0
> 	Root-NFS: no nfs server available, giving up
> 	VFS: Unable to mount fs via NFS, trying floppy
The IP-Config line is missing, also directly before the first NET-4 some
messages
from the network card driver. So your kernel didn't find a network card, but
now tries to get its root-FS via NFS (since you forced it to do that).
This fails because it can't reach the NFS server (sure, there's no
'eth0' ...).
> I think 'rdev <kernelimage> /dev/nfs' is only used as
default, if you don't override it with the kernel option:
rdev sets the 'root='-parameter. It can't do anything about
'nfsroot='. Just forget
it, or look at the other posting about this.

Regards,

Josef

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