One of my colleagues managed to remove glibc using yum, the system was beyond, repairable status and we had to use emergency measures to bring the system up back in to production.After removing glibc using yum, the system was not able to boot, triggering a kernel panic, yum removed more than 1000+ dependencies in a production system, we were not able to chroot, boot etc
1.- We downloaded a RHEL 5.5 iso DVD
2.- Mounted the iso on a system and cp all the rpms under the Server iso directory to a usb rpm.
3.- The following rmps where removed.
If we had more time, we could have done a triage on the packages, but it was 24x7 system, and he agreed to remove any unused packages later.
4.- Started the system in rescue mode using the RHEL 5.5 DVD.
a) Mount the usb
mount /dev/sdb1 /usb
b) Once the usb was mounted we installed/updated all the packages in the Server directory
rpm -ivh --noscripts --force --nodeps --root=/mnt/sysimage /usb/*.rpm
5.- Because a newer version of the iso was used the system was at the same time updated and, it did the trick !!! we booted the system and it was working as before.
a) Config files where respected
b) System was booting and updated to RHEL 5.5