Could not find filesystem ‘

November 6, 2012

could not find filesystem '/dev/root'

I had renamed the LV from LogVol00 to root. So I had made sure I updated the /etc/fstab to reflect the renamed LV.

/dev/VolGroup00/root / ext3 defaults 1 1

It turns out that you also got to make changes to the grub boot menu (/boot/grub/menu.lst) whenever you make changes to the name or location to the root mount.

#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title CentOS (2.6.18-308.4.1.el5) root (hd0,0) kernel /vmlinuz-2.6.18-308.4.1.el5 ro root=/dev/VolGroup00/root initrd /initrd-2.6.18-308.4.1.el5.img
title CentOS (2.6.18-274.3.1.el5) root (hd0,0) kernel /vmlinuz-2.6.18-274.3.1.el5 ro root=/dev/VolGroup00/root initrd /initrd-2.6.18-274.3.1.el5.img
title CentOS (2.6.18-238.9.1.el5) root (hd0,0) kernel /vmlinuz-2.6.18-238.9.1.el5 ro root=/dev/VolGroup00/root initrd /initrd-2.6.18-238.9.1.el5.img
title CentOS (2.6.18-194.32.1.el5) root (hd0,0) kernel /vmlinuz-2.6.18-194.32.1.el5 ro root=/dev/VolGroup00/root initrd /initrd-2.6.18-194.32.1.el5.img
title CentOS (2.6.18-194.17.1.el5) root (hd0,0) kernel /vmlinuz-2.6.18-194.17.1.el5 ro root=/dev/VolGroup00/root initrd /initrd-2.6.18-194.17.1.el5.img

Содержание

1. How to fix?
2. About the Author
3. mount: could not find filesystem /dev/root
4. Re: mount: could not find filesystem /dev/root
5. mount: could not find filesystem /dev/root
6. Re: mount: could not find filesystem /dev/root
7. Re: mount: could not find filesystem /dev/root
8. Re: mount: could not find filesystem /dev/root
9. Re: mount: could not find filesystem /dev/root
10. Re: mount: could not find filesystem /dev/root
11. Re: mount: could not find filesystem /dev/root
12. Re: mount: could not find filesystem /dev/root

How to fix?

Since this error occurs at boot, you will need to boot yourself in RESCUE mode to fix this problem.

chroot /mnt/sysimage/

9. Then go ahead and modify your /boot/grub/menu.lst and modify your kernel line with the updated location of your root partition with your favorite editor.
10. Exit > Exit to reboot.

I hope you found this useful!

About the Author

We have a CentOS 5.3 x64 server that by default runs kernel version 2.6.18-164.11.1 and we are attempting to upgrade the box to 2.6.31.12
The drive is LVM +ext3, and the problem I’m having is when I upgrade the kernel and attempt to boot from it, no matter what version of the kernel I use, I get /dev/root not found towards the end of the boot process, and the kernel panics, and than reboots.

I’m installing the kernel exactly as it says in this doc. I’ve tried it «The centOS way » using make rpm and than installing that. I’ve updated my mkinitrd.
The most interesting part of this problem is that it has been so frustrating that I decided to try and clean install centos on an identical machine without LVM, and the result is EXACTLY the same. After upgrading the kernel, I get /dev/root not found. Does anyone know how to fix this, or what information would be relevant to remedy it? I’m open to try anything at this point.

One more interesting thing about this problem is that in the new version of the kernel, during boot it complains that dm-mapper is started twice, than panics right after that. I’ve tried this with other kernel versions, and the result is the same. What am I missing here?

If you need any more files, please just ask.

 Linux cg 2.6.18-164.11.1.el5 #1 SMP Wed Jan 20 07:32:21 EST 2010 x86_64 x86_64 x86_64 GNU/Linux

 /dev/VolGroup00/LogVol00 / ext3 defaults 1 1 LABEL=/boot /boot ext3 defaults 1 2 tmpfs /dev/shm tmpfs defaults 0 0 devpts /dev/pts devpts gid=5,mode=620 0 0 sysfs /sys sysfs defaults 0 0 proc /proc proc defaults 0 0 /dev/VolGroup00/LogVol01 swap swap defaults 0 0

default=1
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title CentOS (2.6.31.12-rt20) //NOT WORKING!!!! root (hd0,0) kernel /vmlinuz-2.6.31.12-rt20 ro root=/dev/VolGroup00/LogVol00 isolcpus=8,9,10,11,12,13,14,15 panic=10 initrd /initrd-2.6.31.12-rt20.img
title CentOS (2.6.18-164.11.1.el5) //WORKING!! root (hd0,0) kernel /vmlinuz-2.6.18-164.11.1.el5 ro root=/dev/VolGroup00/LogVol00 isolcpus=8,9,10,11,12,13,14,15 panic=10 initrd /initrd-2.6.18-164.11.1.el5.img

slick101

Posts: 35

Joined: 2010/02/19 02:38:34

mount: could not find filesystem /dev/root

Hey guys i was using gparted to add a new drive and when i rebooted i got

slick101

Posts: 35

Joined: 2010/02/19 02:38:34

Re: mount: could not find filesystem /dev/root

by slick101 » 2010/04/21 23:44:53

is it possible to recover /dev I am trying to bootup into linux rescue mode but I am stuck at Enabling HT MSI Mapping

gerald_clark

Posts: 10642

Joined: 2005/08/05 15:19:54

Location: Northern Illinois, USA

mount: could not find filesystem /dev/root

by gerald_clark » 2010/04/22 14:40:38

You have not told us anything useful.
Adding a new drive should have no effect on booting.
If you accidentally re-partitioned and formatted your old drive, there is probably little to be done.

What exactly did you do?

pschaff

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Re: mount: could not find filesystem /dev/root

by pschaff » 2010/04/22 14:55:51

slick101

Posts: 35

Joined: 2010/02/19 02:38:34

Re: mount: could not find filesystem /dev/root

by slick101 » 2010/04/22 15:51:05

You said /dev is created on the fly so I guess thats not the problem I must of deleted the partion to the drive.

I am trying to recover my data right now from a win app, but If iam able to recover the hd back to its state that would be better. But I did not create any backups so, and I am very inexperience in this area =/

I will try linux rescue again with out kernel for another try

pschaff

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Re: mount: could not find filesystem /dev/root

by pschaff » 2010/04/22 17:25:48

If unable to do that then please just show «fdisk -l».

slick101

Posts: 35

Joined: 2010/02/19 02:38:34

Re: mount: could not find filesystem /dev/root

by slick101 » 2010/04/22 18:54:38

So i setup another centos linux box and hooked up my other drive as an external drive but only /boot shows up. Does this mean the data was wiped?

slick101

Posts: 35

Joined: 2010/02/19 02:38:34

Re: mount: could not find filesystem /dev/root

by slick101 » 2010/04/22 18:57:06

Disk /dev/sdb: 80.0 GB, 80000000000 bytes
255 heads, 63 sectors/track, 9726 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

pschaff

Retired Moderator

Posts: 18276

Joined: 2006/12/13 20:15:34

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Re: mount: could not find filesystem /dev/root

by pschaff » 2010/04/22 19:13:47

You lost the top part of the fdisk info, but probably not important for current purposes.

So the new disk was added as the first one? That can be problematic. The 80GB disk has cylinders 14 — 9726 unused. Do you recall how it was originally partitioned? /boot / and swap, just /boot and /, etc.? Were you using LVM (as a default install would do, and as /dev/sda is currently partitioned)? If so then you may just be able to recreate the second partition on /dev/sdb, using all available space, and set it to type 8e — Linux LVM. May still have to play some tricks to boot it as the 2nd disk. Did you do an install to the new disk?

If still having problems can you show grub/grub.conf from /dev/sdb1 — which was presumably the original /boot/ ?

slick101

Posts: 35

Joined: 2010/02/19 02:38:34

Re: mount: could not find filesystem /dev/root

by slick101 » 2010/04/22 19:26:32

Yea I did a clean new install on the new 160G HD. The 80GIG that im trying recover has same setup. Yes I was using LVM default. I just went through a basic setup nothing to advance.

So should i use:

fdisk /dev/sdb1 and use all available space and setup that type?

I am cloning what appears to be a redhat 4 (possibly 5?)server to fairly newer hardware, as the original has a failing board. DBA would rather not reconfigure a new installation so they want me to clone if possible. I used Clonezilla stable release 2.5.0-25 and did 2nd option disk to remote disk copy over network via static IPs. Used this tutorial: https://www.youtube.com/watch?v=8UGR_RLCptQ

Redhat version info:

[root@original_server ~]# cat /etc/redhat-release
redhat-4
#Enterprise Linux Enterprise Linux Server release 5 (Carthage)

Old hardware: Asus RS260/2x Xeon E5420/12gb DDR3 ECC FB RAM (24gb prior to hardware issues)/ICP ICP5085BL RAID controller/RAID 10 8 drives Optimal

New Hardware: Asus RS720/2X Xeon 2620/48gb DDR3 ECC FB RAM/Asus PIKE 2308 RAID Controller/RAID 10 8 drives Optimal

During the process I was not asked to clone the boot loader, though the sda1 partition mounted at /boot appeared to have been cloned afterward.

Long story short it appears the clone was successful and the old data is on the new server in the correct partitions, but when I try to boot I get Unable to access resume device (LABEL=SWAP-sda5) and mount: could not find filesystem '/dev/root'. Then a few more no such file or directory errors then Kernel panic.

So far I’ve tried:

• Installing LSI Fusion-MPT SAS2 driver for el5_3 for RAID via RPM from Asus site.

• Deleting original initrd and rebuilding after doing RAID controller install. initrd file was only very slightly smaller (one or two bytes).

• Getting UUIDs from Gparted for sda1, sda2, sda3, sda6 and modifying /etc/fstab with them instead of the labels.

• Uncommenting #boot=/dev/sda in grub.conf and modifying it to boot=/dev/sda1.

• Modifying kernel command in boot sequence (changing ro to rw, chanting root= to point to /dev/sda, /dev/sda3, and to UUID=uuid of /dev/sda3), none of which worked.

Things I haven’t tried yet that I’m aware are options:

• Reinstalling grub, but do I reinstall to /dev/sda1 (where it originally was) or /dev/sda? And how do I back up the original grub settings prior?

• Installing the RAID controller driver from source (another thing I’m not very familiar with).

• Running fsck: not too familiar, have ran it with -f -y options in the past but apparently you want to run it interactively so as not to break the system.

I’m guessing RAID driver issue, but I’m not sure how to get it included in initrd. If there is a better option for linux system cloning I am open to it (Partimage would not load when I tried it but I can attempt it again). Already spent three days on this so hopefully I’ve done my due diligence prior to asking.

[root@original_server ~]# cat /etc/fstab
LABEL=/ / ext3 defaults 1 1
LABEL=/boot /boot ext3 defaults 1 2
devpts /dev/pts devpts gid=5,mode=620 0 0
tmpfs /dev/shm tmpfs defaults 0 0
LABEL=/main /main ext3 defaults 1 2
LABEL=/opt /opt ext3 defaults 1 2
proc /proc proc defaults 0 0
sysfs /sys sysfs defaults 0 0
LABEL=SWAP-sda5 swap swap defaults 0 0

[root@original_server ~]# cat /boot/grub/grub.conf
# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE: You have a /boot partition. This means that
# all kernel and initrd paths are relative to /boot/, eg.
# root (hd0,0)
# kernel /vmlinuz-version ro root=/dev/sda3
# initrd /initrd-version.img
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,0)/grub/splash.xpm.gz
hiddenmenu
title Enterprise Linux (2.6.18-8.el5)
root (hd0,0)
kernel /vmlinuz-2.6.18-8.el5 ro root=LABEL=/ rhgb quiet
initrd /initrd-2.6.18-8.el5.img

TLDR: Attempted clone of redhat 4 machine to newer hardware over network using Clonezilla and got Could not find filesystem /dev/root. Made modifications to fstab and grub.conf, installed RAID driver, modified boot options, and recreated initrd and same result.

I can provide screenshots or more info if needed. Any help is appreciated, thank you.