After completing install w/ RAID, system won't boot.

kwik_silvr31 · n00b Joined: 14 Nov 2006 Posts: 9

Hi, all. I'm new to this forum, so please excuse me if my issue has already been addressed in a previous topic. I tried searching based upon the issue I am having, and couldn't find anything relevent. Maybe I didn't search hard enough... Also, please keep in mind that you're dealing with someone who's very new to Gentoo. Having said all that...

First off, here is ny system:

Intel D945GTP motherboard
Intel P4 3GHz processor
1 GB RAM (2x512)
3 x Western Digital WD3200YS 320Gig SATA HDDs
Intel E100B Pro Management NIC
Onboard NIC and sound are disabled
Using onboard Intel video controller (should be irrelevent, as I will not be running X on this box)
Sony 52x IDE CDROM
Mitsumi Floppy drive
Antec 350W power supply

The intended purpose of this server will be to host a website for one of my clients. He requires the ability to remote into it through SSH, and he specifically requested Gentoo as his Linux-of-choice. I will be loading MySQL, Apache 2, PHP5 and Image Magic on it for him. Off-topic, I guess, but I just want to be thorough.

I have followed the RAID x86 Quick Install Guide, found at http://www.gentoo.org/doc/en/gentoo-x86+raid+lvm2-quickinstall.xml to the letter, with the following exception: the manual gives as its examlpe a RAID0 configuration for the 4th partition. I wish to use a RAID1 config here. So, where the manual suggested mdadm --create /dev/md4 --level=0 --raid-devices=2 /dev/sda4 /dev/sdb4, I substituted mdadm --create /dev/md4 --level=1 --raid-devices=2 /dev/sda4 /dev/sdb4. In every other instance, I followed the manual exactly. All resultant messages appeared on my system as they are listed in the manual, and the install went fine.

However, after installing GRUB and rebooting per the manual, I am given a No bootable devices found message, which tells me that during the GRUB setup stage, the MBR never got written. I have checked my BIOS settings to make sure the boot order is correct, and that BIOS virus protection was not turned on (which marks track 0 as read-only, if I'm not mistaken).

Can I correct this without having to remirror the drives and/or recompiling the kernel, or is all my work gone? Why, when I issued the setup command within GRUB, did the MBR not get written?

Any suggestions would be very much welcome.

smadasam · Posted: Tue Nov 14, 2006 8:31 pm Post subject:

To me it seems like that either the BIOS is not booting the right drive, or grub was not installed properly to the drive.

You could try selecting diffrent disks to boot from in the BIOS, or

Rebooting to the LiveCD and trying to reinstall grub to the MBR following the Gentoo handbook.

But, in any case, you should be able to get back to your stuff throguh the LiveCD

Have you considered just buying an actual RAID card? I would guess that you could get a decent one for less than $150.
_________________
Intel 486 DX4 100
16 MB RAM
ATI Mach64 2 MB
300 MB HD
14.4 kbps

kwik_silvr31 · n00b Joined: 14 Nov 2006 Posts: 9

Thanks for the reply.

I tried switching the boot order of the hard drives, but to no avail. Again, it appears that the MBR did not get written.

When booting to the LiveCD, I'm unable to get to my partitions because the mirrors they are installed on are unavailable, and mdadm doesn't seem to provide a means for mounting an existing mirrored set.

kwik_silvr31 · n00b Joined: 14 Nov 2006 Posts: 9

Wow... this topic's been in here for quite awhile now, and only one reply... is software RAID something that just isn't normally done?

smadasam · Posted: Wed Nov 15, 2006 10:02 pm Post subject:

Frankly, it is not something that I really do that much.

Software RAID has some fundamental weaknesses regardless of how good the implementation is in software, and it seems like the implementation in Linux is pritty good. The software raid is os dependent which means if something goes wrong in your os, it could corrupt data or worse lose your raid set. Hardware RAID does not care what happens to your os. To you os, it looks like just one SCSI device. So using hardware RAID over software raid is a lot safer for your data, and a lot easier for configuring your os. If you want to be even safer, get a RAID card with a battery back up on the card. If not, make sure your server is at least on an UPS.

Bottomline, $150 or even $500 is a small price to pay for protecting your data and saving your self from headaches.
_________________
Intel 486 DX4 100
16 MB RAM
ATI Mach64 2 MB
300 MB HD
14.4 kbps