Software raid fun…. device detection order
Anyone that’s setup software raid on a system with multiple storage adapters has probably run into this kind of issue, but I thought I’d mention it. Last weekend I built a machine to replace my server (the server was to be captured into a VM). The main system was going to be installed onto dual IDE drives, the VM partition and other data on dual 400GB SATA drives. Well, install went well after getting past some of the irq issues I mentioned in a previous writeup. md0 was /boot and so on…. (md0 residing on the dual ide drives.) When the system went to reboot though it didn’t get very far. It complained of not finding a boot image (I think that was the message – didn’t make a note.)
I tried a reboot a couple times just to try and catch any other messages that I was given (make sure the boot options were in there.) Then it dawned on me that I might be having the SATA adapter detected first…. low and behold… the first sata partitions had become md0 and md1, the /boot partition on the ide drives had become md2. I managed to boot into a recovery console and mount the real root and boot partitions and edit /boot/grub/menu.lst to reflect the CORRECT place to look for the root filesystem.
This all happened on Ubuntu 6.06.1 – I understand that the replacement of init that is due in 7.04 (fiesty fawn) should solve some of these kind of “order of detection” problems. After this was corrected and the boot record reloaded everything went swimmingly and booted up with no further issues.
BTW, software raid is working VERY nicely.