I have found the reason for "mount: only root can do that (effective UID is -2)", The nfs server is NFSv4-powered, NFSv4 has a concept of a root of the overall exported file system. The export point exported with fsid=0 is used as this root. If we didn't specify "fsid=0" in the /etc/exports file, when it is mounted by the NFS client, all the owner of the overall exported file system will become "nfsnobody:nfsnobody". Because of this, the owner of "/bin/mount" is changed to "nfsnobody:nfsnobody" from "root:root". when "mount" is called, the warning message is shown. On Sat, Jun 12, 2010 at 2:47 PM, Min Jun,Xi <xi.minjun@xxxxxxxxx> wrote: > Hi all, > > I am using one NFS directory as the root file system; at first, I use > yum with "--installroot=/tmp/rootimg" option to install all the > necessary rpm packages into "/tmp/rootimg". Then, I added one simple > dracut module into the rootimg (which only output some information > indeed), and I run "chroot /tmp/rootimg dracut xxx" to generate the > "initrd.gz" file. > > I updated my kernel command lines like this: > ++++++++++++++++++++++++++++++++++ > #netboot rhel6-ppc64-compute > timeout=5 > image=xcat/netboot/rhel6/ppc64/compute/kernel > label=xcat > initrd=xcat/netboot/rhel6/ppc64/compute/initrd.gz > append="root=nfs4:192.168.11.107:/tmp/rootimg:rw ip=dhcp > rdshell rdinfo rdinitdebug" > +++++++++++++++++++++++++++++++++++ > > The diskless node can be booted, but with some error/warning messages > during the scripts under /etc/init.d/ are being executed. You can see > them from the following message. > > ++++++++++++++++++++++++++++++++++++++++++++++++++ > + exec switch_root /sysroot /sbin/init > mount: only root can do that (effective UID is -2) > Welcome to Red Hat Enterprise Linux Server > Press 'I' to enter interactive startup. > Starting udev: [ OK ] > Setting hostname ca4dsls02: [ OK ] > Setting up Logical Volume Management: No volume groups found > [ OK ] > Checking filesystems > WARNING: couldn't open /etc/fstab: No such file or directory > Checking all file systems. > [ OK ] > mount: only root can do that (effective UID is -2) > Mounting local filesystems: mount: only root can do that (effective UID is -2) > [FAILED] > chgrp: changing group of `/var/run/utmp': Invalid argument > chgrp: > changing group of `/var/log/wtmp': Invalid argument > > chown: changing ownership > of `/tmp/.ICE-unix': Invalid argument > Enabling /etc/fstab swaps: swapon: /etc/fstab: open failed: No such > file or directory > > [FAILED] > Entering non-interactive startup > Retrigger failed udev events[ OK ] > Starting sshd: /var/empty/sshd must be owned by root and not group or > world-writable. > [FAILED] > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > So, here, I have several questions, > 1) why does "mount: only root can do that (effective UID is -2)" show > here? what can I do to make it not show here? > > 2) "/etc/fstab" is not there, should I create one before switching > root to the NFS mountpoint? > > 3) "chgrp" and "chown" fails here, should I prepare the directories > myself before switching root? > > Thank you! > -- best regards, Xi Minjun xCAT Development Team Member in CDL,IBM Notes ID: Min Jun Xi/China/IBM/ -- To unsubscribe from this list: send the line "unsubscribe initramfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
