Here is how you can create the problem. Make a copy of your "fstab" corrupt the "fstab" to simulate a failed disk and reboot. It drops you to the maintenance prompt and asks you for a password - at this point you are done. The only rescue scheme we have found is to reinstall the system, recreate the disk partitions, - failed disk, do not format partitions and after it writes a new "fstab", bail out - power off and restart. System come up minus failed disk and everything works. Discovered this early late Sunday evening after a disk failure and major power failure to facility at the same time. Rude and Crude but it works.
Larry Linder On Thursday 02 February 2012 5:19 pm, Yasha Karant wrote: > I have been discussing the failure mode that I have observed: > > also documented in > > https://bugzilla.redhat.com/show_bug.cgi?id=636628 > > after fsck fails during a (re)boot > > Give root password for maintenance > (or type Control-D to continue): > > At this stage, at every second key stroke, it reports "Login incorrect." > and repeats the above "Give root password...". > > as an endless loop. > > The argument has been presented on this list that it is the root user > failure to configure a password into grub.conf or other bootloading or > initialization applications/routines configuration or input data files. > > I have been discussing this issue with a number of experienced systems > persons, and none of us accept this argument, especially as without > special intervention or configuration, the expected behavior was > displayed on EL 4 and 5, as well as several other non-TUV distributions. > Expected behavior: whatever root password was encoded into the > /etc/shadow file is used by the routine that handles "Give root password > for maintenance" is accepted, and not at every second key stroke would > it report "Login incorrect." > > When the system is first installed from physical media such as a > bootable DVD (for EL, this is with every major release, e.g., EL 4, EL > 5, EL 6, etc.), and a root password is required to be set during > installation, this password is put in an encrypted form in the > appropriate file in /etc (e.g., /etc/shadow) and wherever else it might > be required (e.g., in /boot if the particular implementation were to > require this). Moreover, for fsck to run during the boot process, even > if /boot is on a separate partition from / (root partition), the fsck > executable is on a partition that must have been mounted, and thus > /etc/shadow should be available. Hence, the (encrypted) password should > be available. > > The bug is that the password entry routine (as in response to the prompt > "Give root password for maintenance") does not accept the full vector of > characters for the root password including the Enter keystroke that > terminates the vector. > > As there are correspondents to this list that evidently feel the above > arguments to be incorrect, references to the relevant Linux source code > sections and design documents (e.g., state machine chart for the > sequence that contains "Give root password for maintenance") greatly > would be appreciated. > > Yasha Karant
