You are testing failover with reboots. So when Linux probes the disks, it is putting "hdc" where "hda" used to be.... This seems a bit strange, as hda/hdb should theoretically be IDE1 and hdc/hdd should be IDE2.... As far as your grub setup, it looks perfectly fine. You should have two entries as you have, because if disc1 fails, you cannot boot to hd(0,0) and vice-versa. One gotcha, make sure grub is installed in the MBR of BOTH drives, not just the MD device.... Thanks, Tom Callahan TESSCO Technologies Inc. 410-229-1361 -----Original Message----- From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid-owner@xxxxxxxxxxxxxxx]On Behalf Of Hari Bhaskaran Sent: Monday, October 31, 2005 10:57 AM To: linux-raid@xxxxxxxxxxxxxxx Subject: s/w raid and bios renumbering HDs Hi, I am trying to setup a RAID-1 setup for the boot/root partition. I got the setup working, except what I see with some of my tests leave me less convinced that it is actually working. My system is debian 3.1 and I am not using the raid-setup options in the debian-installer, I am trying to add raid-1 to an existing system (followed http://www.tldp.org/HOWTO/Software-RAID-HOWTO.html -- 7.4 method 2) I have /dev/hda (master on primary) and /dev/hdc (master on secondary) setup as mirrors. I also have a cdrom on /dev/hdd. Now if I disconnect hda and reboot, everything seems work - except what used to be /dev/hdc comes up as /dev/hda. I know this since I the bios does complain that "primary disk 0" is missing and I would have expected a missing hda, not a missing hdc. Anyways, the software seems to recognize the "failed-disk" fine if I connect the real hda back. Is this the way it is supposed to work? Can I rely on this? Also what happens when I move on to fancier setups like raid5?. My box is a dell 400sc with some phoenix bios (doesnt have many options either). I get different (still unexpected) results with the cdrom connected and not. Question #2 (probably related to my problem) My grub menu.lst is as follows (/dev/md0 is made of /dev/hda1 and /dev/hdc1) For testing, I made two entries (one for (hd0,0) and another for (hd1,0)). The howto I was reading wasn't clear to me. Should I be making just one entry pointing to /dev/md0? Also trying labels for "hda" and "hdc" after connecting the faulty drive back gave me different results ( in one case I was looking at "older" data and in the other case I wasn't) (ignore the vs2.1.xxx. it is a linux-vserver patch - shouldn't matter here) title Debian GNU/Linux, kernel 2.6.13.3-vs2.1.0-rc4-RAID-hda root (hd0,0) kernel /boot/vmlinuz-2.6.13.3-vs2.1.0-rc4 root=/dev/md0 ro initrd /boot/initrd.img-2.6.13.3-vs2.1.0-rc4.md0 savedefault boot title Debian GNU/Linux, kernel 2.6.13.3-vs2.1.0-rc4-RAID-hdc root (hd1,0) kernel /boot/vmlinuz-2.6.13.3-vs2.1.0-rc4 root=/dev/md0 ro initrd /boot/initrd.img-2.6.13.3-vs2.1.0-rc4.md0 savedefault boot Any help is appreciated. If there is a better/current HOWTO, please let me know. The ones I have seen so far refer to now deprecated tools (raidtools or raidtools2) and I have had a hard time trying to find the equivalent syntax for mdadm. -- Hari - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
