Bug 210738

I am seeing this too -- after upgrading to FC6 on both server and diskless
client mount is having severe problems.  Disclaimer: I'm using a homegrown
diskless setup on the client which has a slightly modified FC userland. 
However, my investigations so far indicate that this is a legitimate FC bug.

The symptom I am seeing is that the boot pauses for several minutes after
printing the "Remounting root filesystem in read-write mode".  Eventually the
system does boot but root ends up being mounted twice and the overlaid one is in
read-only mode, causing lots of things to fail.

I added some debugging to /etc/rc.d/rc.sysinit and found that the line that it's
pausing on:

  # Enter mounted filesystems into /etc/mtab
  mount -f /

That ought to be pretty innocuous -- the "-f" flag after all SHOULD prevent any
actual mount from happening.  This doesn't seem to work on NFS mounts, however.

Running that mount command under "strace -f" I see:

  execve("/sbin/mount.nfs", ["/sbin/mount.nfs", "MY-SERVER:/MY/PATH", "/", "-o",
"rw"], [/* 18 vars */]) = 0

So it seems that when /bin/mount calls /sbin/mount.nfs it forgets to pass along
the "-f" flag, causing breakage.  I verified that calling mount.nfs with "-f"
seems to work just fine.  I suspect this might be the root cause of the problem

Can we get some action on this?

Hellooo? netboot is completely broken, so I would expect a little more attention
to this bug.

Are you really sure that your initrd.img actually contains the /sbin/mount.nfs
binary at all ? In my case the "system-config-netboot-0.1.41-1.FC6.noarch"
package is forgetting (?) to copy/include the /sbin/mount.nfs into the
initrd.img and therefore you get a cryptic mount error while the diskless client
tries to mount the root-device from the NFS-server.

By making the one line change below, the NFS-mount succeeds just fine
(ie. copy the /sbin/mount.nfs into initrd.img)

This broke in FC5 and the last kernel which worked without this modification as
2.6.17-2187 (in my case at least)

Regards,
Tomi Orava

--- /usr/share/system-config-netboot/diskless/updateDiskless    2007-01-21
20:46:42.000000000 +0200
+++ /usr/share/system-config-netboot/diskless/updateDiskless.mod       
2007-01-21 17:48:43.000000000 +0200
@@ -114,7 +114,7 @@
 done;
 #/bin/cp "$ROOT"/usr/share/hwdata/pcitable $MNTPOINT/usr/share/hwdata/ || die;
 # disklessrc now uses modules.pcimap, not pcitable
-BINS="/sbin/busybox.anaconda /sbin/insmod /sbin/modprobe /sbin/rmmod
/sbin/dhclient /bin/bash /bin/mount /sbin/route /sbin/ip /usr/bin/expr
/sbin/lspci /sbin/ifconfig /sbin/consoletype /sbin/pivot_root /bin/hostname
/bin/domainname /usr/bin/host"
+BINS="/sbin/busybox.anaconda /sbin/insmod /sbin/modprobe /sbin/rmmod
/sbin/dhclient /bin/bash /bin/mount /sbin/mount.nfs /sbin/route /sbin/ip
/usr/bin/expr /sbin/lspci /sbin/ifconfig /sbin/consoletype /sbin/pivot_root
/bin/hostname /bin/domainname /usr/bin/host"
 # Set up links to all the busybox functions -
 # may be different for different versions of busybox!
 if [ ! -e $ROOT/sbin/busybox.anaconda ]; then 

Now that's a very plausible explanation. I'll test it later tonight.

Works like a charm! Please apply ASAP!

/sbin/mount.nfs is only the beginning... it goes over, mounts nfs root, there
appear some error which scrolls quickly, then it seems to lock after selinux
prints on screen... after a while I get some message on 'vfs ... lockmanager'
(don't remember well).

This is the same bug as 227903

https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=227903

The workaround that works for me is make that mount -f -i /.

Helloooo? Could we have this fixed?

fixed in 0.1.42