Date: Fri, 18 Apr 2003 14:28:03 -0500 (CDT) From: Eduardo Viruena Silva <mrspock@esfm.ipn.mx> To: freebsd-questions@freebsd.org Subject: question about diskless Message-ID: <20030418123246.W15059@Gina.esfm.ipn.mx>
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Hi list!
I finally made my diskless FreeBSD FreeBSD 5.0-RELEASE work.
I have some questions that you surely can answer.
1. While booting, FreeBSD-5.0 diskless boot scripts try to make
an fsck on the network file systems that they are mounting.
The system stops, asking for help and complains about the
absence of /usr/sbin/fsck_nfs. Take a look
------------------------------------------------------------
Starting file system checks:
fsck: exec /usr/sbin/fsck_nfs for 192.168.123.112:/usr/diskless/rootfs: No
such file or directory
fsck: exec /usr/sbin/fsck_nfs for 192.168.123.112:/usr/diskless/rootfs: No
such file or directory
Unknown error; help!
Apr 18 11:52:10 init: /bin/sh on /etc/rc terminated abnormally, going to
single user mode
Enter full pathname of shell or RETURN for /bin/sh:
------------------------------------------------------------
** It must be noticed that /etc/rc.d/fsck is the script that
** tries to make the file system check.
It makes no sense to me that it must to be done.
Network file systems [or just directories!] are supposed
to be working in another computer and I don't see why [and how]
they have to be checked. Am I right?
I made a very simple script that says:
========== fsck_nfs ==========
#!/bin/sh
echo $0 $*
exit 0
==============================
Of course, it makes nothing but displaying the command
that was used to make fsck_nfs, its parameters, and
returning no error.
With this script I got:
------------------------------------------------------------
/sbin/fsck_nfs -p -F 192.168.123.112:/usr/diskless/rootfs
192.168.123.112:/usr/diskless/rootfs:
DEFER FOR BACKGROUND CHECKING
/sbin/fsck_nfs -p -F 192.168.123.112:/usr/diskless/rootfs/usr
192.168.123.112:/usr/diskless/rootfs/usr: DEFER FOR BACKGROUND CHECKING
/sbin/fsck_nfs -p -F 192.168.123.112:/usr/X11R6
192.168.123.112:/usr/X11R6: DEFER FOR BACKGROUND CHECKING
nfs: can't update /var/db/mounttab for 192.168.123.112:/usr/diskless/rootfs
------------------------------------------------------------
and the booting process continues. However, if you notice it,
this script is located in /sbin not in /usr/sbin.
The last line is also worth of consideration. /var is still a
read-only file system when all of this happens.
2. When the booting process starts, there is another problem if
/etc/resolv.conf does not exist. Before we begin we have to make
some considerations.
This is my configuration in my DHCP server:
=====================
ddns-update-style none;
subnet 192.168.123.0 netmask 255.255.255.0 {
option domain-name "mydomain.mine";
option domain-name-servers 192.168.123.112;
option routers 192.168.123.254;
default-lease-time 600;
max-lease-time 7200;
host Lucia {
fixed-address 192.168.123.37;
hardware ethernet 00:03:47:19:c5:b1;
option root-path "192.168.123.112:/usr/diskless/rootfs";
option host-name "Lucia.mydomain.mine";
filename "/boot/pxeboot";
}
}
======================
I could not understand why I have to set explicitly:
option host-name "Lucia.mydomain.mine";
inside the entry of "Lucia". Ok, I don't care, it is already set.
Now, suppose that /etc/resolv.conf does not exist in the diskless
file system. In /etc/rc.d/initdiskless, lines 129-140:
130 # if the info is available via dhcp/kenv
131 # build the resolv.conf
132 #
133 if [ ! -e /etc/resolv.conf ]; then
134 echo domain `kenv dhcp.domain-name` > /etc/resolv.conf
135
136 set `kenv dhcp.domain-name-servers`
137 for ns in `IFS=','; echo $*`; do
138 echo nameserver $ns >> /etc/resolv.conf;
139 done
140 fi
line 133 asks if /etc/resolv.conf does not exist. It is our case.
Now, line 134 asks for dhcp.domain-name variable and tries to write
"domain " and the value of this variable in /etc/resolv.conf
The problem here is that diskless root file system is still read-only.
===========
kenv: unable to get dhcp.domain-name
/etc/rc.d/initdiskless: cannot create /etc/resolv.conf: Read-only file
system
===========
Well, as you can see this is not the only problem. "kenv" does not
have "dhcp.domain-name". Perhaps I am making something wrong in
my DHCP configuration, if so, please, let me know.
Of course, the obvious solution is to create /etc/resolv.conf and
forgive this matter.
But, if you print the kernel environment variables [kenv], none of them
begins with "dhcp."
I hope you can help me.
Thanks in advance.
Eduardo
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