rebuilt RAID array, no longer able to mount root

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adpowers · Post by **adpowers** » Wed Feb 25, 2004 2:36 am

Howdy.

My new Gentoo server was running well for a few months (it had an uptime of like 60+ days). However, when I got back from a vacation on Sunday, it wasn't responding to SSH, Samba, or anything else. This has happened once before. So, I do a hard shut down and bring a monitor and keyboard to plug in. While booting, it says my RAID 5 is degraded. I attempt to rebuild it, but still one of the drives is not in use. However, I was still able to boot into Gentoo and use the machine. Today I purchased a new drive (so I don't have to wait to get a new one under warranty), installed it, and started rebuilding the array. It loaded Grub, then started into Linux. That is when I get this error message:

VFS: Cannot open root device "sda3" or 08:03
Please append a correct "root=" boot option
Kernel Panic: VFS: Unable to mount root fs on 08:03

My RAID card is the 3ware 7500(?) (it is the 8 port Serial ATA one). It makes the computer think it is a SCSI drive and that is how it was working before. I can't imagine what happened to make it stop working all of a sudden. The root filesystem is ReiserFS. I don't know what information you need, so just ask and I'll try to provide it. Could the RAID array been assigned to a different hard drive name (like sda3 or whatever)? I tried hitting tab in the Grub configuration thing (to show me what names were available) and it said file not found (or something along those lines). Also, is there anyway to boot off a floppy or CD and list the partitions?

Any help would be very much appreciated. My important information was backed up, but I have dozens of gigs of media files that took me a long time to collect and I would hate to lose them.

Andrew

onegative · Post by **onegative** » Wed Feb 25, 2004 5:15 am

First of all i wanna say i'm not an expert of raid configuration under linux or even under windows.

That said, i can tell you what i would try.

I would boot a gentoo live cd (or whatever distro live cd you have) and do a #fdisk sda. Check your partitions to see if all is still there. Inside fdisk, do "p" to print partitions.

Is your /boot on the raid array too?

o-negative

adpowers · Post by **adpowers** » Wed Feb 25, 2004 7:48 am

Okay, I'll try the boot disk tomorrow.

It loads into RAM and doesn't affect the hard drives, does it? Also, it will take me to a command prompt after loading, correct?

Yeah, the /boot is on the RAID array. Everything was put on that. It must work somewhat if it can load Grub and part of the kernel.

I'll get back to you tomorrow.
Thanks again,
Andrew

adpowers · Post by **adpowers** » Thu Feb 26, 2004 1:28 am

Okay, I booted off a slightly older Gentoo CD (the same one I used to install).

I loaded the doscsi thing because the 3ware card imitates a SCSI drive. Once in, I tried running fdisk. The only drive it could find was /dev/hda, the CD drive (I believe). It returned no responses for /dev/sda.

Another side point, occasionally, while booting, the RAID card doesn't recognize drive 6, causing it to say imcomplete (because drive 2 hasn't been rebuilt yet).

When booting, I sometimes notice something that says like: "3ware: unable to flush AEN" or something like that.

Upon inspection of the 3ware website, I see that they released a firmware fix for the 8506-8 and other cards running in dual processor systems including the AMD MPX while running a degraded RAID 5 array. It causes it to sometimes not boot. This is strikingly similar to my situation. I'll check out what firmware I'm running later tonight.

Andrew

PS: Sorry for all the potential off-topic paragraphs above. I'm trying to include anything that may be relevant. Also, I want to provide options for people facing similar problems.