View Full Version : [ubuntu] 8.04 Alternate CD + Software RAID = worthless?

May 11th, 2008, 01:04 PM
I can't figure out what is going on but I cannot get the Alternate installer to install to a software raid array and have system not fail miserably.

The goal is:

/dev/sda1 = 100MB = /boot
/dev/sda2 = 3.9GB = raid
/dev/sdb2 = 3.9GB = raid
/dev/sdc2 = 3.9GB = raid
/dev/sdd2 = 3.9GB = raid

those 4 partition are put in raid 0...
/dev/md0 = ~15GB = /

Now any reason this won't work? First problem is if I use the installer to setup this partitioning after it is done if I switch to another console and check /proc/mdstat md0 says its on /dev/sda /dev/sdb /dev/sdc /dev/sdd.... this is WRONG!!! its supposed to be /dev/sda2 /dev/sdb2 and so on.

If I just try using the installer it appears to install but after first reboot things go to crap and kernel loads but cant find root partition. The array seems to be seen but says it has no file system on it, and probably cause it thinks its over the entire drive and not just the 2nd parttion.

If I try to manually set up the partitioning and and array correct... then go back to the installer and let just format the parttion... it looks like it'll work but doesn't.

Anyways.... I give up for the moment... any way to do a manual install off the live cd? more like a gentoo install, like step by step?

May 22nd, 2008, 08:25 PM
Unlike you, I did the upgrade from 7.10 to 8.04 at work, on our webserver. It wouldn't boot after.

Specs: AMD Opteron - 64 bit Kernel, 4GB Mem, 2 HDD in RAID 1 (root and boot) and 3 HDD in Raid 5 (/home).

The BIOS says all the drives are there on the POST screen, but once the kernel boots, it says that it couldn't find the SATA channel on the drives. Of course mdadm craps out at point and says that the md's are disconnected.

Once I boot with the old kernel (thank goodness that I didn't remove it on upgrade) everything boots as expected.

This looks like a major flaw in the kernel.

May 22nd, 2008, 09:56 PM
Hi, it indeed seems to be a bug in the kernel. I found the solution on this page:


You can find the discussion at the "SATA drives not detected in IDE mode (DELL users mainly)" point.

More specifically here is the bug workaround:


I am going to try this later.

May 23rd, 2008, 09:23 PM
Ok... here is some more:

It looks like the mdadm failed on my part because Hardy uses "sda, sdb, sdc, ..." instead of Gutsy's "hda, hdb, ... "

This could be part of why my raid array is dying.

I will post if I find out more. BTW, this is where I found this latest though: