Christopher Chan wrote: > Ugo Bellavance wrote: >> jancio_wodnik at wp.pl wrote: >>> Christopher Chan pisze: >>>> >>>>>>>> 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. >>> Yeap, this is true. After installing centos4 on RAID1 disk (software >>> raid) i always do: >>> >>> grub >>> grub>device (hd0) /dev/hdc >>> grub>root (hd0,0) grub>setup (hd0) >>> >>> where /dev/hdc is second RAID DISK (it could be whatever: /dev/sdb1 etc) >>> >>> So system is booting form first or second riad1 disk >> >> Ok, so to sum up from what I understand of my problem: >> >> Installation of CentOS4 -> Installs grub only on one HDD partition out >> of 2, in the mirror. > > Well, I believe you chose md0 or something to install grub on right? > >> >> One disk fails, the one that has grub > > Not necessarily. All it takes is a change in the sequence of disk > assignment. > >> >> System won't boot because it can't find grub on the other drive. > > Correct. It needs to be instructed to look on its own drive. > >> >> If I had centos5 there in the first place, the setup would have taken >> care of installing grub on the 2 mirrored raid partitions. >> >> Am I right? > > Yes. > >> >> Is there a way to know where grub is installed? I have a few servers >> running in RAID 1 software for /boot, I gotta fix this. If I can't >> tell whether it is installed or not, is it dangerous to re-install it >> using the command above? >> > > So long as you have all the necessary grub files, there is not much > danger. Even if you are missing a config file on this side of the mirror > (impossible...) so long as you load grub stage 2, you will have the > power you need to continue if you have access (eg: via serial) I was talking about all my others centos4 machines..