[RAID] Another Grub issue leading to a dead computer

take look at

https://wiki.ubuntu.com/Raid
https://wiki.ubuntu.com/DmraidSupport
https://bugs.launchpad.net/ubuntu/+source/ubiquity/+bug/864195
https://help.ubuntu.com/community/FakeRaidHowto

the fakeRAID is not a true RAID (as the name implies), it is just a 'beefed up' SATA controller on the MB and is highly proprietary.
it relies heavily on BIOS and proprietary software. for 10.10 release there is apparently a workable solution fact witnessed and mentioned by you above.

I'd recommend to stay with 10.10 release until this issue is solved on the other releases or,

acquire a TRUE RAID controller that supports ANY os.

Hi,

I have already visited most of these links (except the third one), but thank you.

I am aware that a fakeRAID is not a real RAID, but I don't understand why it worker perfectly with Ubuntu 10.10 and earlier, and does not work at all since 11.04. It just does not make sense to me.

After trying an other clean install of Ubuntu, I ended up getting the same error message again, except that now, when I boot my computer, I have Grub Rescue instead of the BASH-like command thing.

I just realized that I did not give the error message in my first message, here it is :
"Executing 'grub-install /dev/sda' failed.
This is a fatal error."

If I press "OK", it gives me three choices : Trying to install Grub on another partition, continue without a bootloader, and cancel the installation.

No matter what partition I chose, it either tells me instantly that the installation is done and asks me to reboot (obviously, grub doesn't work), or tells me that it didn't work and ask me to chose one of the three choices again (I always end up having to chose "Continue without a bootloader".

Is there really no solution to this ?...

well, you could see that a bug on this issue has already been filed; it is a situation that will be addressed by the dev team. this kind of problems are to be expected on ANY new release of an os be it proprietary or open source.

moreover, the free open source os's like linux/ubuntu rely v little on BIOS ; I dare say that the BIOS in open source systems is just an impediment (and I'd say a major one) that creates lots of problems. in open source os everything is done by the os software starting with hwre detection and configuration; the BIOS task is, basically, to just enable a bus so that the os install media can be read, nothing more.

I never tried installing ubuntu on a fakeRAID but on the alternate CD install media, during install procedure, I could see that dmraid is loaded and, if I'm not mistaken, on the partitioner phase there is an option to install on a RAID config. I also do not know whether this would be possible in a dual boot situation (when the fakeRAID WAS already set up by BIOS/proprietary software). I'd say/recommend to give it a try - get an ubuntu alternate CD media and see what happens; do not forget - before proceeding MAKE SURE that you have on hand RELIABLE backups

the sure way for the time being, see above, is to stay with 10.10 for the time being, that is until this bug is sorted out by the dev team.

another solution, if you want to use the latest release, is to break the current fakeRAID (end up with 2 independent HD) and install the os's on one of them and use the second one as your data repository/storage.

my personal experience with fakeRAID's is quite bad- they are extremely unreliable- they must be synchronized on regular basis , the fail unexpectedly etc etc.

Hm...
And I guess it is not possible to break a fakeRAID without wiping the whole content of both hard drives ?

Would it be possible to get, like, Windows 7 on the first hard drive and Ubuntu on the second one, while using Grub to chose on which OS to boot ?

Sometimes I get the Ubuntu 11.10 installer to try to install Grub on /dev/dm-0 (Which is what Ubuntu 10.10 does when I install it), but it fails anyway...

yes, ALL RAID metadata must be purged off both HD in order to make them function/operate as separate drives. as you know RAID configurations can be of many kinds - striped, mirrored, jbond ; you must know what your RAID config is. for sure the RAID docs and utilities used to create it will tell you how to remove/break it. do yourself a favour and follow these procedures to the letter to save a lot of aggravation later.

first BACK UP your data NOT the os (the os can be installed any time provided that you are the proud owner of a proprietary os LICENCE; ubuntu is an open source os) then consult your specific RAID manual how to remove/break the RAID 'bonds' - for sure you have to act on BIOS as well as on the software that created it in the first place; on what to act FIRST the manual should tell it you; it is important.

...'Would it be possible to get, like, Windows 7 on the first hard drive and Ubuntu on the second one, while using Grub to chose on which OS to boot ?'... the answer is yes but... consider this

question pls : why would you like to to install the os's on two diff HD's ? personally I like to keep the os on a separate HD while DATA sits nicely on another/second HD - why ? if the os experiences problems and can not be booted into or the HD fails your DATA is still there on the second HD and can be retrieved (the os or HD failure WILL not take down with it your DATA).

I'd recommend to install win on the first pri partition of the first HD (mr Gates os mandatory requires this; make this part large enough to accommodate just win and all its updates and applications plus 20-25% additional/reserve space) ; LEAVE the remaining space on the drive unpartitioned (in linux parlance it is called FREE SPACE); make sure that after win install done it functions flawlessly - v imp.

then during ubuntu install create an extended partition on the remaining FREE SPACE and within it create logical partitions for it (minimum 2 - one / and swap). after ubuntu install finished you'll have a perfectly functioning dual boot system with a grub menu where win and ubuntu boot options are displayed.

log into ubuntu and use gparted utility to configure the second HD; create partitions as you desire with file systems that can be seen (read and written to) by BOTH os's like ntfs, fat32 etc.

for your info - on the first HD (in linux it is /dev/sda) lives the MBR where grub lives.