>>>> grub cannot find its second stage. Are you booting from a mirrored >>>> partition? >>> >>> Yes >> >> What could be a solution? And what could have happen upon the reboot? > > That is weird. I just re-installed centos5 and it is now booting > properly. What could I do to avoid this situation in the future? > IIRC, RHEL4 does not properly handle installation of grub on mirrored partitions and therefore Centos4 suffers from the same problem. RHEL5 does it properly now as you can see. This has been a long outstanding problem of anaconda.