Boot partition won't mount, superblock error

Itserpol · n00b Joined: 23 Jan 2010 Posts: 22

Hi all. This is my second time installing Gentoo, and I'm not sure what's happening here.

When I boot Gentoo, it displays the following error about my boot partition (sdb1)

Jaglover · Posted: Fri Feb 05, 2010 7:44 am Post subject:

/boot does not need to be mounted, bootloader reads it at an early boot stage and boots the kernel from there. Once the kernel is loaded into RAM there is no need to access /boot.
Situation you describe is possible when ext2 support is built as module, thus not available before / is mounted.

patrikas · Tux's lil' helper Joined: 28 Nov 2009 Posts: 106

Isn't the root file system the one which gets mounted first since it is pointed by bootloader ?

Firstly check ext2 support in .config. Last time I installed gentoo I had similar problem because ext2 was not selected by default and I didn't notice that.

Jaglover · Posted: Fri Feb 05, 2010 9:38 am Post subject:

Itserpol,

your error will go away if you set noauto option for /boot as per handbook.

@patrikas

Itserpol · n00b Joined: 23 Jan 2010 Posts: 22

Thanks for the quick replies!

As for ext2 support, I double checked and it is indeed built into the kernel (not as a module).
Is there any way I can fix this so that I don't have manually mount /boot? That could get a little annoying...

Jaglover · Posted: Sat Feb 06, 2010 10:47 am Post subject:

Why you need to mount /boot all the time? It does not need to be mounted for Gentoo to function.
Anyhow, look into dmsg.

Itserpol · n00b Joined: 23 Jan 2010 Posts: 22

Well okay, I guess you're right. I really don't need to have /boot mounted all the time. But the same superblock error keeps coming up every time I start Gentoo. If I were to recreate the partition (after backing up my kernel and grub data of course), could that solve it?

Mike Hunt · Watchman Joined: 19 Jul 2009 Posts: 5287

But do mount boot before copying a new kernel to it.

Please post the output of

Itserpol · n00b Joined: 23 Jan 2010 Posts: 22

Mike Hunt · Watchman Joined: 19 Jul 2009 Posts: 5287

Ok, now we need to see your /boot/grub/grub.conf please.

Itserpol · n00b Joined: 23 Jan 2010 Posts: 22

Itserpol · n00b Joined: 23 Jan 2010 Posts: 22

I finally got around to recreating the boot partition and it didn't help, making me think it may be a hardware problem (I have had problems with this disk before).

Also, is it normal to have a symbolic link from /boot to /boot? I thought I could do without it when copying my backup data back onto the partition, but apparently grub can't find the kernel without it.

John R. Graham · Posted: Thu Feb 11, 2010 2:42 pm Post subject:

Yes, it's normal. It's a convention so that your grub.conf kernel line looks the same whether /boot is on an independent mounted filesystem or just a directory off of your root filesystem. You could get rid of the symbolic link and then just specify your kernel line like

Itserpol · n00b Joined: 23 Jan 2010 Posts: 22

First I booted to my Gentoo liveUSB and started fdisk.

Mike Hunt · Watchman Joined: 19 Jul 2009 Posts: 5287

... and? Was rebooting successful?

Itserpol · n00b Joined: 23 Jan 2010 Posts: 22

Well, yeah. The rebooting went just fine. But the repartitioning didn't fix anything. I'm exactly where I was when I started.

John R. Graham · Posted: Fri Feb 12, 2010 4:31 pm Post subject:

Could you post the output of

Itserpol · n00b Joined: 23 Jan 2010 Posts: 22

BrummieJim · l33t Joined: 22 Jul 2005 Posts: 683

Sorry if I'm hijacking this thread, but I have exactly the same problem, but it's on my root partition. My system was working fine before I updated the system with an emerge world on saturday. The system still boots fine, just boot and home aren't mounted. Home still has data on it, as I can mount it from a knoppix boot.

I have a knoppix USB device so I was going to run e2fsck on the partition without mounting it, is this a bad idea?

Is this a hardward fault and a sign of an aging drive? Had the computer for about two years.

Jaglover · Posted: Wed Feb 17, 2010 1:19 am Post subject:

Did you forget running dispatch-conf.
Can you still mount those partitions from your Gentoo by hand. If not, what's the error message.

BrummieJim · l33t Joined: 22 Jul 2005 Posts: 683

In my case you can't mount any of the partitions as the /dev/sda doesn't exist.

I've run dispatch-conf and am running a revdep-rebuild now.

Any more suggestions?
Jim

BrummieJim · l33t Joined: 22 Jul 2005 Posts: 683

trying ae2fsck -b 32768 /dev/sda7, but it comes up with lots of errors, I hit y to fix, but still gentoo can't detect the patitions.

Knoppix has no problem.

hendric · n00b Joined: 02 Mar 2014 Posts: 3

I was running into the same problem (boot partition does not mount by default, error listed in dmesg is "couldn't mount as ext2 due to feature incompatibility", but mount /dev/sda2 /boot worked fine) during my first install. I want /boot mounted as I will be experimenting with the kernel and need to change it frequently.

I did some testing, and here is what I found out.

Changing the filesystem type from ext2 to auto for grub2 seems to make it work, however dmesg still reports some complaints from EXT4-fs

(sda2): couldn't mount as ext3 due to feature incompatibilities
(sda2): couldn't mount as ext2 due to feature incompatibilities
(sda2): mounted filesystem with ordered data mode. Opts: (null)

mount reports
/dev/sda2 on /boot type ext4 (rw, noatime)

So I tried ext4 in /etc/fstab, and now /boot mounts fine.

My suspicion ss the installation for grub2 is overwriting the ext2 configuration done in the earlier step. Sound likely?

FWIW, I am installing into a VirtualBox VM, using a 64 bit OS.

Hu · Administrator Joined: 06 Mar 2007 Posts: 21706