Linux RAID-1 [3]

So at the end of the last post the system had not been able to startup because of a problem mounting the RAID array and the LiveUSB could not start the system because the Nouveau drivers had problems. As it happens all that is needed is to change some parameters in the LiveUSB Grub bootloader and these are similar to the ones I had to put into MainPC’s bootloader to get it to start when it was first installed. I’m using the Lubuntu USB installer because the Mint one seems to have some corruption and the loader kept reporting problems with the USB ports and hubs. In the Lubuntu one you need to at the initial menu move the selection to “Try Lubuntu without installing” and then press e to edit the boot parameters, look for some text that reads “quiet splash” and replace it with “nomodeset” and possibly also “text”. It would seem Nouveau issues are quite common out there and this works around those problems. See http://ubuntuforums.org/showthread.php?t=2289050

Once you have Lubuntu going then open LXTerminal and we need to mount the boot disk to somewhere convenient e.g, /mount/boot so make a boot directory inside /mount and then mount the boot volume to it. Lubuntu LiveCD allows you to use sudo without a password but if you want to take a shortcut and use su then you need some password and a blank one doesn’t work. But that seems to be OK anyhow because sudo works well enough. Or you can just open the Disks tool from the Preferences section of the menu and it will mount the volume to a path inside /media so that is what I worked with in the end. Once I had got used to the fact I was working with the fstab in this path and not the /etc/fstab from the LiveUSB boot it was a simple step to comment out the line for /newhome’s mount, and then the system rebooted and here I am writing the rest of this post from it.

This time I am doing all the steps starting from checking the RAID modules are loaded in the kernel. Well indeed the two modules needed, raid and md, are not being loaded in the kernel at startup so I followed the steps needed to make them load, however md is not installed and I can’t find it as a package to install. I left that for now and went onto trying to sort out the array itself. A check with the Disks gui tool found that the array is not running. Rebooting (with the raid1 module now being loaded at startup) did not fix the problem. So I deleted the partition and now there is no RAID array reported so it is back to creating a new partition to see if I can make things work from here. Once I had the new partition I decided for good measure to recreate /dev/sdd1 from scratch as well, deleted the partition and created it from scratch, again all OK so it appears. With the disks looking like back to normal I went back to do the mdadm create command again and again it appeared to create normally and so the array is resyncing. This time both disks appear to be reporting as members of the array in all the commands I can run (last time it seems only one disk was reported) so maybe it is working better this time.

So I have to wrap up Part 3 of this series for now, leaving the new RAID-1 array to resync properly for a few hours and getting on with some other things, as my system is otherwise working well with its home partition on the removable drive caddy, then hopefully we can come back and maybe it will all work this time, but I am concerned about the missing md module which could still cause problems. However as I have been working on getting the system up and going for the best part of a day I have to leave it for now and come back to it later this afternoon once it has finished syncing the array. So a Part 4 of this series is coming.