LinuxQuestions.org
Download your favorite Linux distribution at LQ ISO.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Software
User Name
Password
Linux - Software This forum is for Software issues.
Having a problem installing a new program? Want to know which application is best for the job? Post your question in this forum.

Notices



Reply
 
Search this Thread
Old 01-26-2012, 01:17 AM   #1
rarebear.nm
LQ Newbie
 
Registered: Jan 2012
Posts: 10

Rep: Reputation: Disabled
CentOS 6.1 RAID 1 boot failure on sdb


I have a fresh build of CentOS 6.1 on a HP DL160G6 server. I built the OS on a set of software mirrors. I first made RAID partitions then created RAID 1 devices in the OS install process. So /boot is on md0 (ext3), / is on md1 (ext3) and other mount points on other md_. This is very much a typical install of CentOS 6.1. The system boots fine with both drives inserted and is also fine with only sda inserted. But it fails to boot when I have only sdb inserted.

I have read many posts about booting from mirrored drives, but the parts dealing with installing grub on the second drive fail with errors. I think I have a simple error but I do not know what or where is it.

I did copy the MBR from sda to sdb via
dd if=/dev/sda of=/dev/sdb bs=512 count=1
This just copies the first 512 bytes of sda to the first 512 bytes of sdb.

In /boot/grub/grub.conf I added "fallback=1"after "default=0"
/boot/grub/grub.conf shows: root (hd1,4)

I have tried the following and always get errors as shown:
grub> root (hd0,0)
Filesystem type unknown, partition type 0xfd

grub> find /boot/grub/stage1
Error 15: File not found

File stage1 is very much found in /boot/grub at 512 bytes.

md0 is /boot and is made up of sda5 & sdb5
md1 is / and is made up of sda1 & sdb1


Can anyone provide instructions that work to boot from eiher sda or sdb in this configuration?

Last edited by rarebear.nm; 01-26-2012 at 01:38 AM.
 
Old 01-26-2012, 02:57 AM   #2
brak44
Member
 
Registered: Aug 2010
Location: Brisbane Australia
Distribution: Centos, Fedora
Posts: 85

Rep: Reputation: 24
CentOS 6 and RAID1

With both disks installed

On the GRUB shell, type in the following commands:

grub> root (hd0,0)

grub> setup (hd0)

grub> root (hd1,0)

grub> setup (hd1)

Also please be aware that there is a bug with kernel 2.6.32-220.2.1.el6.x86_64 and/or dracut which affects the boot process when only one disk is installed.
Details here:
https://bugzilla.redhat.com/show_bug.cgi?id=772926
http://bugs.centos.org/view.php?id=5400
 
Old 01-26-2012, 03:15 AM   #3
rarebear.nm
LQ Newbie
 
Registered: Jan 2012
Posts: 10

Original Poster
Rep: Reputation: Disabled
Thanks for the reply. I have already done that, as partly noted in my first post. When I do:

grub> root (hd0,0)
Filesystem type unknown partitin type 0xfd

grub> setup (hd0)
Error 1 Cannot mount selected partition

I get same errors for (hd1,0) and (hd1)

grub> find /boot/grub/stage1
Error 15: File not found
(/boot/grub/stage1 is present)

I think if I can clear these errors, then it will work. But what is going on here? This is brand new install, nothing updated or changed.
 
Old 01-26-2012, 04:01 AM   #4
rarebear.nm
LQ Newbie
 
Registered: Jan 2012
Posts: 10

Original Poster
Rep: Reputation: Disabled
Part of the problem with the grub commands was using :
grub> root (hd0,0)
grub> setup (hd0)

grub> root (hd1,0)
grub> setup (hd1)

This threw errors (CentOS 6.1) I think it would work in CentOS 5.x
Also did grub> find /grub/grub.conf instead of grub> /boot/grub/stage1 (which failed)
This showed:
(hd0,4) & (hd1,4)

When I used:
grub> root (hd0,4)
grub> setup (hd0)

grub> root (hd1,4)
grub> setup (hd1)

The errors disappeard and I got what looks like normal completin messages. instead.

However, objective still not done. Boot from sdb still fails... where next??

Can anyone post a working example of grub.conf file for CentOS 6.1 with mirrored boot partitions (sda & sdb)?

Last edited by rarebear.nm; 01-26-2012 at 04:14 AM.
 
Old 01-26-2012, 04:05 AM   #5
brak44
Member
 
Registered: Aug 2010
Location: Brisbane Australia
Distribution: Centos, Fedora
Posts: 85

Rep: Reputation: 24
Please post the results of
cat /proc/mdstat
mdadm --detail /dev/md0
mdadm --detail /dev/md1
mdadm --detail /dev/md2

Note that a typical mdadm raid assignment will have md0 as boot, md1 as swap & md2 as /
 
Old 01-26-2012, 04:23 AM   #6
rarebear.nm
LQ Newbie
 
Registered: Jan 2012
Posts: 10

Original Poster
Rep: Reputation: Disabled
Personalities : [raid1]
md9 : active raid1 sda11[0] sdb11[1]
51198908 blocks super 1.1 [2/2] [UU]
bitmap: 0/1 pages [0KB], 65536KB chunk

md8 : active raid1 sdb9[1]
20478908 blocks super 1.1 [2/1] [_U]
bitmap: 1/1 pages [4KB], 65536KB chunk

md7 : active raid1 sda8[0] sdb8[1]
20478908 blocks super 1.1 [2/2] [UU]
bitmap: 0/1 pages [0KB], 65536KB chunk

md6 : active raid1 sdb7[1]
20478908 blocks super 1.1 [2/1] [_U]
bitmap: 1/1 pages [4KB], 65536KB chunk

md5 : active raid1 sda6[0] sdb6[1]
20478908 blocks super 1.1 [2/2] [UU]
bitmap: 0/1 pages [0KB], 65536KB chunk

md4 : active raid1 sda3[0] sdb3[1]
20478908 blocks super 1.1 [2/2] [UU]
bitmap: 0/1 pages [0KB], 65536KB chunk

md3 : active raid1 sda10[0] sdb10[1]
20478908 blocks super 1.1 [2/2] [UU]
bitmap: 0/1 pages [0KB], 65536KB chunk

md2 : active raid1 sda2[0] sdb2[1]
20478908 blocks super 1.1 [2/2] [UU]

md1 : active raid1 sda1[0] sdb1[1]
20478908 blocks super 1.1 [2/2] [UU]
bitmap: 1/1 pages [4KB], 65536KB chunk

md0 : active raid1 sda5[0] sdb5[1]
204788 blocks super 1.0 [2/2] [UU]

unused devices: <none>

cat mtab is:

/dev/md1 / ext3 rw 0 0
proc /proc proc rw 0 0
sysfs /sys sysfs rw 0 0
devpts /dev/pts devpts rw,gid=5,mode=620 0 0
tmpfs /dev/shm tmpfs rw,rootcontext="system_ubject_r:tmpfs_t:s0" 0 0
/dev/md0 /boot ext3 rw 0 0
/dev/md3 /home ext4 rw 0 0
/dev/md7 /opt ext4 rw 0 0
/dev/md4 /tmp ext4 rw 0 0
/dev/md5 /usr ext4 rw 0 0
/dev/md6 /usr/local ext4 rw 0 0
/dev/md8 /var ext4 rw 0 0
/dev/md9 /var/log ext4 rw 0 0
none /proc/sys/fs/binfmt_misc binfmt_misc rw 0 0
/dev/sdc1 /usb vfat rw 0 0


md0 is /boot
md1 is /

/dev/md0:
Version : 1.0
Creation Time : Mon Jan 23 14:47:47 2012
Raid Level : raid1
Array Size : 204788 (200.02 MiB 209.70 MB)
Used Dev Size : 204788 (200.02 MiB 209.70 MB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent

Update Time : Thu Jan 26 02:26:17 2012
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0

Name : localhost.localdomain:0
UUID : b980e09a:169f1704:82ca7e0e:fe169cd7
Events : 26

Number Major Minor RaidDevice State
0 8 5 0 active sync /dev/sda5
1 8 21 1 active sync /dev/sdb5
/dev/md1:
Version : 1.1
Creation Time : Mon Jan 23 14:47:52 2012
Raid Level : raid1
Array Size : 20478908 (19.53 GiB 20.97 GB)
Used Dev Size : 20478908 (19.53 GiB 20.97 GB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent

Intent Bitmap : Internal

Update Time : Thu Jan 26 02:26:25 2012
State : active
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0

Name : localhost.localdomain:1
UUID : ec034380:3d694c33:2ab12136:eedd1cd7
Events : 105

Number Major Minor RaidDevice State
0 8 1 0 active sync /dev/sda1
1 8 17 1 active sync /dev/sdb1
/dev/md3:
Version : 1.1
Creation Time : Mon Jan 23 14:48:03 2012
Raid Level : raid1
Array Size : 20478908 (19.53 GiB 20.97 GB)
Used Dev Size : 20478908 (19.53 GiB 20.97 GB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent

Intent Bitmap : Internal

Update Time : Thu Jan 26 02:00:54 2012
State : active
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0

Name : localhost.localdomain:3
UUID : 060d56ef:33421a75:7c695ab6:81a4b2e8
Events : 82

Number Major Minor RaidDevice State
0 8 10 0 active sync /dev/sda10
1 8 26 1 active sync /dev/sdb10

I have 10 partions, each one software mirrored at time the OS was installed.

Last edited by rarebear.nm; 01-26-2012 at 04:33 AM.
 
Old 01-26-2012, 05:22 AM   #7
brak44
Member
 
Registered: Aug 2010
Location: Brisbane Australia
Distribution: Centos, Fedora
Posts: 85

Rep: Reputation: 24
Your making it too hard for yourself.
> I have 10 partitions
Why?
I'd recommend that you start again with just 3, i.e. boot, swap & /
as per http://www.centos.org/docs/5/html/De...id-config.html

You will need to remove existing raid metadata using a live cd
e.g.
mdadm --stop /dev/md3
mdadm --zero-superblock /dev/sdd1
Remove partition & raid flag using gparted
 
Old 01-26-2012, 03:08 PM   #8
rarebear.nm
LQ Newbie
 
Registered: Jan 2012
Posts: 10

Original Poster
Rep: Reputation: Disabled
This is public facing server and I have always partioned in a similar fashion to provide additinal levels of hardening when mounting certain directories. I have a hard time believing that booting from mirrored drives is impacted by having more than 3 partitions.

In your notes are you refering to md3 in the present setup or md3 in a three partition setup? Can you please expand on use gparted somewhat?

Thanks,

Last edited by rarebear.nm; 01-26-2012 at 04:21 PM.
 
Old 01-28-2012, 11:12 PM   #9
rarebear.nm
LQ Newbie
 
Registered: Jan 2012
Posts: 10

Original Poster
Rep: Reputation: Disabled
Solved

Problem is solved.

The solution was:
1. open grub
2. grub> find /grub/grub.conf
3. This will provide some thing like:
(hd0,2)
(hd1,2)
4. root (hd0,2)
5. setup (hd0)
6. root (hd1,2)
7. setup (hd1)
8. quit grub
9. Do not edit grub.conf, do not add a line like "fallback 1" as some posts state. This may work for CentOS5.x or prior, but not for CetOS6.1

My entire problem was adding the fallback 1 line to grub.conf.
 
Old 04-27-2012, 07:29 AM   #10
sv1cec
LQ Newbie
 
Registered: Apr 2012
Posts: 6

Rep: Reputation: Disabled
I have what I think is a similar issue. But please forgive me if it is not, I am no great expert of Centos.

I just finished installing Centos on a dual disk RAID 1 system.

Here are the results of some commands:

#cat /proc/mdstat
Personalities : [raid1]
md0 : active raid1 sdc1[1] sdb1[0]
511988 blocks super 1.0 [2/2] [UU]

md2 : active raid1 sdb3[0] sdc3[1]
57041852 blocks super 1.1 [2/2] [UU]
bitmap: 1/1 pages [4KB], 65536KB chunk

md1 : active raid1 sdc2[1] sdb2[0]
1048568 blocks super 1.1 [2/2] [UU]

unused devices: <none>



#mdadm --detail /dev/md0
/dev/md0:
Version : 1.0
Creation Time : Wed Apr 25 12:57:31 2012
Raid Level : raid1
Array Size : 511988 (500.07 MiB 524.28 MB)
Used Dev Size : 511988 (500.07 MiB 524.28 MB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent

Update Time : Thu Apr 26 15:33:46 2012
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0

Name : www.xxxx.org:0 (local to host www.xxxx.org)
UUID : e1d1e60b:ae93ae26:3a70119e:9615f50d
Events : 21

Number Major Minor RaidDevice State
0 8 17 0 active sync /dev/sdb1
1 8 33 1 active sync /dev/sdc1


#mdadm --detail /dev/md1
/dev/md1:
Version : 1.1
Creation Time : Wed Apr 25 12:57:33 2012
Raid Level : raid1
Array Size : 1048568 (1024.16 MiB 1073.73 MB)
Used Dev Size : 1048568 (1024.16 MiB 1073.73 MB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent

Update Time : Thu Apr 26 15:34:00 2012
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0

Name : www.xxxx.org:1 (local to host www.xxxx.org)
UUID : b1563c86:8011a6a7:ad02f052:7c20ef48
Events : 19

Number Major Minor RaidDevice State
0 8 18 0 active sync /dev/sdb2
1 8 34 1 active sync /dev/sdc2


#mdadm --detail /dev/md2
/dev/md2:
Version : 1.1
Creation Time : Wed Apr 25 12:57:34 2012
Raid Level : raid1
Array Size : 57041852 (54.40 GiB 58.41 GB)
Used Dev Size : 57041852 (54.40 GiB 58.41 GB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent

Intent Bitmap : Internal

Update Time : Thu Apr 26 15:36:42 2012
State : active
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0

Name : www.xxxx.org:2 (local to host www.xxxx.org)
UUID : d317e3d8:25633e80:3632ee4a:0ca5dad1
Events : 776

Number Major Minor RaidDevice State
0 8 19 0 active sync /dev/sdb3
1 8 35 1 active sync /dev/sdc3

And here is my grub.conf (as it was created from the installation):

# 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 (hd1,0)
# kernel /vmlinuz-version ro root=/dev/md2
# initrd /initrd-[generic-]version.img
#boot=/dev/md0
default=0
timeout=5
splashimage=(hd1,0)/grub/splash.xpm.gz
hiddenmenu
title CentOS (2.6.32-220.13.1.el6.i686)
root (hd1,0)
kernel /vmlinuz-2.6.32-220.13.1.el6.i686 ro root=UUID=5202ffed-2272-4338-ba45-7b85ee4cf1bd rd_NO_LUKS KEYBOARDTYPE=pc KEYTABLE=us LANG=en_US.UTF-8 quiet SYSFONT=latarcyrheb-sun16 rhgb crashkernel=auto rd_MD_UUID=d317e3d8:25633e80:3632ee4a:0ca5dad1 rd_NO_LVM rd_MD_UUID=b1563c86:8011a6a7:ad02f052:7c20ef48 rd_NO_DM
initrd /initramfs-2.6.32-220.13.1.el6.i686.img
title CentOS (2.6.32-220.el6.i686)
root (hd1,0)
kernel /vmlinuz-2.6.32-220.el6.i686 ro root=UUID=5202ffed-2272-4338-ba45-7b85ee4cf1bd rd_NO_LUKS KEYBOARDTYPE=pc KEYTABLE=us LANG=en_US.UTF-8 quiet SYSFONT=latarcyrheb-sun16 rhgb crashkernel=auto rd_MD_UUID=d317e3d8:25633e80:3632ee4a:0ca5dad1 rd_NO_LVM rd_MD_UUID=b1563c86:8011a6a7:ad02f052:7c20ef48 rd_NO_DM
initrd /initramfs-2.6.32-220.el6.i686.img


The problem:

When both disks are attached to the computer, everything works fine. If however, I power the system down and remove the first disk, I get a "Hard Disk Error". If I remove the second disk, I get a grub prompt. That is not exactly what I had in mind when creating the array.

System details:

Centos 6.2 with the latest updates.
Dracut is the latest version which is supposed to correct the bug shown at whirlpool forums under archive 1848637 (sorry, this is my first post and I am not allowed to post a link)

I installed from a netinstall CD, and I placed the boot loaded on md0, after I have defined the partitions and the RAID devices.

Would the above solution be of help to me? Or is there something else I should do?
Any help in troubleshooting my RAID array would, of course, be greatly appreciated.

Last edited by sv1cec; 04-27-2012 at 07:46 AM.
 
Old 04-27-2012, 10:53 AM   #11
yancek
Guru
 
Registered: Apr 2008
Distribution: PCLinux, Slackware
Posts: 5,102

Rep: Reputation: 815Reputation: 815Reputation: 815Reputation: 815Reputation: 815Reputation: 815Reputation: 815
Quote:
When both disks are attached to the computer, everything works fine. If however, I power the system down and remove the first disk, I get a "Hard Disk Error". If I remove the second disk, I get a grub prompt. That is not exactly what I had in mind when creating the array.
The above would indicate that you have Grub in the master boot record of the second disk pointing to the / partition on the first disk resulting in the errors you see. I don't use RAID and am not familiar with it. I'm not really sure what your intentions are or "what I had in mind..." as stated above.

You could get detailed boot information by downloading and running the bootinfoscript:

http://sourceforge.net/projects/bootinfoscript/

Post it here if you need to.
 
Old 04-27-2012, 11:06 AM   #12
sv1cec
LQ Newbie
 
Registered: Apr 2012
Posts: 6

Rep: Reputation: Disabled
What I wanted to create is a system which will have two disks in the array. In case one of the disks fail, I just remove it and replace it with another. Just as a safety measure, since I have no way to have backups of my entire disk (tapes etc).

I'll download and run that program and report back.

Many thanks
 
Old 04-27-2012, 02:04 PM   #13
sv1cec
LQ Newbie
 
Registered: Apr 2012
Posts: 6

Rep: Reputation: Disabled
Here are the results of the bootinfoscipt.

Boot Info Script 0.61 [1 April 2012]


============================= Boot Info Summary: ===============================

=> Windows is installed in the MBR of /dev/sda.
=> Grub Legacy0.970.97 is installed in the MBR of /dev/sdb and looks at
sector 543204 on boot drive #1 for the stage2 file. A stage2 file is at
this location on /dev/sdb. Stage2 looks on partition #1 for
/grub/grub.conf..

sda1: __________________________________________________________________________

File system: linux_raid_member
Boot sector type: Grub Legacy
Boot sector info: Grub Legacy (v0.97) is installed in the boot sector
of sda1 and looks at sector 543204 on boot drive #2
for the stage2 file. A stage2 file is at this
location on /dev/sdb. Stage2 looks on partition #1
for /grub/grub.conf.

sda2: __________________________________________________________________________

File system: linux_raid_member
Boot sector type: Unknown
Boot sector info:

sda3: __________________________________________________________________________

File system: linux_raid_member
Boot sector type: Unknown
Boot sector info:

sdb1: __________________________________________________________________________

File system: linux_raid_member
Boot sector type: Grub Legacy
Boot sector info: Grub Legacy (v0.97) is installed in the boot sector
of sdb1 and looks at sector 543204 on boot drive #2
for the stage2 file. A stage2 file is at this
location on /dev/sdb. Stage2 looks on partition #1
for /grub/grub.conf.

sdb2: __________________________________________________________________________

File system: linux_raid_member
Boot sector type: Unknown
Boot sector info:

sdb3: __________________________________________________________________________

File system: linux_raid_member
Boot sector type: Unknown
Boot sector info:

md1: ___________________________________________________________________________

File system: swap
Boot sector type: -
Boot sector info:

md2: ___________________________________________________________________________

File system: ext4
Boot sector type: -
Boot sector info:
Operating System: CentOS release 6.2 (Final)
Kernel on an
Boot files: /etc/fstab

md0: ___________________________________________________________________________

File system: ext4
Boot sector type: Grub Legacy
Boot sector info: Grub Legacy (v0.97) is installed in the boot sector
of md0 and looks at sector 543204 on boot drive #2 for
the stage2 file. A stage2 file is at this location on
/dev/sdb. Stage2 looks on partition #1 for
/grub/grub.conf.
Operating System:
Boot files: /grub/menu.lst /grub/grub.conf

============================ Drive/Partition Info: =============================

Drive: sda _____________________________________________________________________

Disk /dev/sda: 60.0 GB, 60011642880 bytes
255 heads, 63 sectors/track, 7296 cylinders, total 117210240 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes

Partition Boot Start Sector End Sector # of Sectors Id System

/dev/sda1 * 2,048 1,026,047 1,024,000 fd Linux raid autodetect
/dev/sda2 1,026,048 3,123,199 2,097,152 fd Linux raid autodetect
/dev/sda3 3,123,200 117,209,087 114,085,888 fd Linux raid autodetect


Drive: sdb _____________________________________________________________________

Disk /dev/sdb: 60.0 GB, 60011642880 bytes
255 heads, 63 sectors/track, 7296 cylinders, total 117210240 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes

Partition Boot Start Sector End Sector # of Sectors Id System

/dev/sdb1 * 2,048 1,026,047 1,024,000 fd Linux raid autodetect
/dev/sdb2 1,026,048 3,123,199 2,097,152 fd Linux raid autodetect
/dev/sdb3 3,123,200 117,209,087 114,085,888 fd Linux raid autodetect


"blkid" output: ________________________________________________________________

Device UUID TYPE LABEL

/dev/md0 e6910e66-82e2-4c59-97f8-7dd0a86ab4d1 ext4
/dev/md1 0ff5f9dc-2c1d-47fb-b089-d2151c476ace swap
/dev/md2 5202ffed-2272-4338-ba45-7b85ee4cf1bd ext4
/dev/sda1 e1d1e60b-ae93-ae26-3a70-119e9615f50d linux_raid_member www.xxxxxxxxx.org:0
/dev/sda2 b1563c86-8011-a6a7-ad02-f0527c20ef48 linux_raid_member www.xxxxxxxxx.org:1
/dev/sda3 d317e3d8-2563-3e80-3632-ee4a0ca5dad1 linux_raid_member www.xxxxxxxxx.org:2
/dev/sdb1 e1d1e60b-ae93-ae26-3a70-119e9615f50d linux_raid_member www.xxxxxxxxx.org:0
/dev/sdb2 b1563c86-8011-a6a7-ad02-f0527c20ef48 linux_raid_member www.xxxxxxxxx.org:1
/dev/sdb3 d317e3d8-2563-3e80-3632-ee4a0ca5dad1 linux_raid_member www.xxxxxxxxx.org:2

================================ Mount points: =================================

Device Mount_Point Type Options

/dev/md0 /boot ext4 (rw)
/dev/md2 / ext4 (rw)


================================ md2/etc/fstab: ================================

--------------------------------------------------------------------------------

#
# /etc/fstab
# Created by anaconda on Wed Apr 25 16:17:26 2012
#
# Accessible filesystems, by reference, are maintained under '/dev/disk'
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
UUID=5202ffed-2272-4338-ba45-7b85ee4cf1bd / ext4 defaults 1 1
UUID=e6910e66-82e2-4c59-97f8-7dd0a86ab4d1 /boot ext4 defaults 1 2
UUID=0ff5f9dc-2c1d-47fb-b089-d2151c476ace swap swap defaults 0 0
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
--------------------------------------------------------------------------------

============================= md0/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 (hd1,0)
# kernel /vmlinuz-version ro root=/dev/md2
# initrd /initrd-[generic-]version.img
#boot=/dev/md0
default=0
timeout=5
splashimage=(hd1,0)/grub/splash.xpm.gz
hiddenmenu
title CentOS (2.6.32-220.13.1.el6.i686)
root (hd1,0)
kernel /vmlinuz-2.6.32-220.13.1.el6.i686 ro root=UUID=5202ffed-2272-4338-ba45-7b85ee4cf1bd rd_NO_LUKS KEYBOARDTYPE=pc KEYTABLE=us LANG=en_US.UTF-8 quiet SYSFONT=latarcyrheb-sun16 rhgb crashkernel=auto rd_MD_UUID=d317e3d8:25633e80:3632ee4a:0ca5dad1 rd_NO_LVM rd_MD_UUID=b1563c86:8011a6a7:ad02f052:7c20ef48 rd_NO_DM
initrd /initramfs-2.6.32-220.13.1.el6.i686.img
title CentOS (2.6.32-220.el6.i686)
root (hd1,0)
kernel /vmlinuz-2.6.32-220.el6.i686 ro root=UUID=5202ffed-2272-4338-ba45-7b85ee4cf1bd rd_NO_LUKS KEYBOARDTYPE=pc KEYTABLE=us LANG=en_US.UTF-8 quiet SYSFONT=latarcyrheb-sun16 rhgb crashkernel=auto rd_MD_UUID=d317e3d8:25633e80:3632ee4a:0ca5dad1 rd_NO_LVM rd_MD_UUID=b1563c86:8011a6a7:ad02f052:7c20ef48 rd_NO_DM
initrd /initramfs-2.6.32-220.el6.i686.img
--------------------------------------------------------------------------------

==================== md0: Location of files loaded by Grub: ====================

GiB - GB File Fragment(s)

0.258790970 = 0.277874688 grub/grub.conf 2
0.258790970 = 0.277874688 grub/menu.lst 2
0.258161545 = 0.277198848 grub/stage2 1
0.050032616 = 0.053722112 initramfs-2.6.32-220.13.1.el6.i686.img 2
0.030742645 = 0.033009664 initramfs-2.6.32-220.el6.i686.img 2
0.034803391 = 0.037369856 vmlinuz-2.6.32-220.13.1.el6.i686 1
0.015270233 = 0.016396288 vmlinuz-2.6.32-220.el6.i686 2

======================== Unknown MBRs/Boot Sectors/etc: ========================

Unknown BootLoader on sda2

00000000 fc 4e 2b a9 01 00 00 00 00 00 00 00 00 00 00 00 |.N+.............|
00000010 b1 56 3c 86 80 11 a6 a7 ad 02 f0 52 7c 20 ef 48 |.V<........R| .H|
00000020 77 77 77 2e xx xx xx xx xx xx xx xx xx 2e 6f 72 |www.xxxxxxxxx.or|
00000030 67 3a 31 00 00 00 00 00 00 00 00 00 00 00 00 00 |g:1.............|
00000040 8d ca 97 4f 00 00 00 00 01 00 00 00 00 00 00 00 |...O............|
00000050 f0 ff 1f 00 00 00 00 00 00 00 00 00 02 00 00 00 |................|
00000060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000080 10 00 00 00 00 00 00 00 f0 ff 1f 00 00 00 00 00 |................|
00000090 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000000a0 00 00 00 00 00 00 00 00 a0 f2 7a f0 78 ed a3 43 |..........z.x..C|
000000b0 f8 7c 8c 73 57 5c e0 65 00 00 00 00 00 00 00 00 |.|.sW\.e........|
000000c0 6d 74 9a 4f 00 00 00 00 13 00 00 00 00 00 00 00 |mt.O............|
000000d0 ff ff ff ff ff ff ff ff 9d 7e 24 83 80 01 00 00 |.........~$.....|
000000e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000100 00 00 01 00 fe ff fe ff fe ff fe ff fe ff fe ff |................|
00000110 fe ff fe ff fe ff fe ff fe ff fe ff fe ff fe ff |................|
*
00000200

Unknown BootLoader on sda3

00000000 fc 4e 2b a9 01 00 00 00 01 00 00 00 00 00 00 00 |.N+.............|
00000010 d3 17 e3 d8 25 63 3e 80 36 32 ee 4a 0c a5 da d1 |....%c>.62.J....|
00000020 77 77 77 2e xx xx xx xx xx xx xx xx xx 2e 6f 72 |www.xxxxxxxxx.or|
00000030 67 3a 32 00 00 00 00 00 00 00 00 00 00 00 00 00 |g:2.............|
00000040 8e ca 97 4f 00 00 00 00 01 00 00 00 00 00 00 00 |...O............|
00000050 78 c7 cc 06 00 00 00 00 00 00 00 00 02 00 00 00 |x...............|
00000060 08 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000070 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000080 00 08 00 00 00 00 00 00 00 c8 cc 06 00 00 00 00 |................|
00000090 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000000a0 00 00 00 00 00 00 00 00 06 34 f9 d4 b1 2f 50 94 |.........4.../P.|
000000b0 82 0d 97 c2 20 60 f8 f2 00 00 00 00 00 00 00 00 |.... `..........|
000000c0 7b dd 9a 4f 00 00 00 00 09 03 00 00 00 00 00 00 |{..O............|
000000d0 00 00 00 00 00 00 00 00 07 61 f5 4d 80 01 00 00 |.........a.M....|
000000e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000100 00 00 01 00 fe ff fe ff fe ff fe ff fe ff fe ff |................|
00000110 fe ff fe ff fe ff fe ff fe ff fe ff fe ff fe ff |................|
*
00000200

Unknown BootLoader on sdb2

00000000 fc 4e 2b a9 01 00 00 00 00 00 00 00 00 00 00 00 |.N+.............|
00000010 b1 56 3c 86 80 11 a6 a7 ad 02 f0 52 7c 20 ef 48 |.V<........R| .H|
00000020 77 77 77 2e xx xx xx xx xx xx xx xx xx 2e 6f 72 |www.xxxxxxxxx.or|
00000030 67 3a 31 00 00 00 00 00 00 00 00 00 00 00 00 00 |g:1.............|
00000040 8d ca 97 4f 00 00 00 00 01 00 00 00 00 00 00 00 |...O............|
00000050 f0 ff 1f 00 00 00 00 00 00 00 00 00 02 00 00 00 |................|
00000060 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000080 10 00 00 00 00 00 00 00 f0 ff 1f 00 00 00 00 00 |................|
00000090 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000000a0 01 00 00 00 00 00 00 00 5f d7 54 11 43 3d 88 5e |........_.T.C=.^|
000000b0 b8 bd 2f 7d 68 54 d9 43 00 00 00 00 00 00 00 00 |../}hT.C........|
000000c0 6d 74 9a 4f 00 00 00 00 13 00 00 00 00 00 00 00 |mt.O............|
000000d0 ff ff ff ff ff ff ff ff f8 eb 7e a6 80 01 00 00 |..........~.....|
000000e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000100 00 00 01 00 fe ff fe ff fe ff fe ff fe ff fe ff |................|
00000110 fe ff fe ff fe ff fe ff fe ff fe ff fe ff fe ff |................|
*
00000200

Unknown BootLoader on sdb3

00000000 fc 4e 2b a9 01 00 00 00 01 00 00 00 00 00 00 00 |.N+.............|
00000010 d3 17 e3 d8 25 63 3e 80 36 32 ee 4a 0c a5 da d1 |....%c>.62.J....|
00000020 77 77 77 2e xx xx xx xx xx xx xx xx xx 2e 6f 72 |www.xxxxxxxxx.or|
00000030 67 3a 32 00 00 00 00 00 00 00 00 00 00 00 00 00 |g:2.............|
00000040 8e ca 97 4f 00 00 00 00 01 00 00 00 00 00 00 00 |...O............|
00000050 78 c7 cc 06 00 00 00 00 00 00 00 00 02 00 00 00 |x...............|
00000060 08 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000070 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000080 00 08 00 00 00 00 00 00 00 c8 cc 06 00 00 00 00 |................|
00000090 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
000000a0 01 00 00 00 00 00 00 00 05 0a b4 88 b5 c8 47 fd |..............G.|
000000b0 74 a9 7f 28 66 68 aa 7b 00 00 00 00 00 00 00 00 |t..(fh.{........|
000000c0 7b dd 9a 4f 00 00 00 00 09 03 00 00 00 00 00 00 |{..O............|
000000d0 00 00 00 00 00 00 00 00 42 74 42 59 80 01 00 00 |........BtBY....|
000000e0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
*
00000100 00 00 01 00 fe ff fe ff fe ff fe ff fe ff fe ff |................|
00000110 fe ff fe ff fe ff fe ff fe ff fe ff fe ff fe ff |................|
*
00000200


=============================== StdErr Messages: ===============================

File descriptor 12 (pipe:[124418]) leaked on lvscan invocation. Parent PID 21857: /bin/bash
File descriptor 13 (pipe:[124418]) leaked on lvscan invocation. Parent PID 21857: /bin/bash
No volume groups found
 
Old 04-28-2012, 03:52 AM   #14
sv1cec
LQ Newbie
 
Registered: Apr 2012
Posts: 6

Rep: Reputation: Disabled
OK, I applied the solution proposed by rarebear in post #9 above, and we went one step ahead, but not all the way to the end.

Now, if I remove either disk from the system, simulating a hard disk failure, I no longer get the error messages I was getting before, but I get the boot count down and a correct kernel version number. However, when the count-down ends, instead of booting, I am thrown back at the BIOS start-up screen and the system tries to reboot again. And again and again.

I was thinking:

In my grub.conf file, I have:

# 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 (hd1,0)
# kernel /vmlinuz-version ro root=/dev/md2
# initrd /initrd-[generic-]version.img
#boot=/dev/md0
default=0
timeout=5
splashimage=(hd1,0)/grub/splash.xpm.gz
hiddenmenu
title CentOS (2.6.32-220.13.1.el6.i686)
root (hd1,0)
kernel /vmlinuz-2.6.32-220.13.1.el6.i686 ro root=UUID=5202ffed-2272-4338-ba45-7b85ee4cf1bd rd_NO_LUKS KEYBOARDTYPE=pc KEYTABLE=us LANG=en_US.UTF-8 quiet SYSFONT=latarcyrheb-sun16 rhgb crashkernel=auto rd_MD_UUID=d317e3d8:25633e80:3632ee4a:0ca5dad1 rd_NO_LVM rd_MD_UUID=b1563c86:8011a6a7:ad02f052:7c20ef48 rd_NO_DM
initrd /initramfs-2.6.32-220.13.1.el6.i686.img
title CentOS (2.6.32-220.el6.i686)
root (hd1,0)
kernel /vmlinuz-2.6.32-220.el6.i686 ro root=UUID=5202ffed-2272-4338-ba45-7b85ee4cf1bd rd_NO_LUKS KEYBOARDTYPE=pc KEYTABLE=us LANG=en_US.UTF-8 quiet SYSFONT=latarcyrheb-sun16 rhgb crashkernel=auto rd_MD_UUID=d317e3d8:25633e80:3632ee4a:0ca5dad1 rd_NO_LVM rd_MD_UUID=b1563c86:8011a6a7:ad02f052:7c20ef48 rd_NO_DM
initrd /initramfs-2.6.32-220.el6.i686.img


As you see, the system tries to find the kernel etc in hd1. However, when you boot with only one disk in the system, hd1 shouldn't exist, right? So I think that these references should point to hd0, instead of hd1, in order for the system to find a kernel to load, when starting with only one disk. Am I correct in that?
 
Old 04-28-2012, 03:40 PM   #15
lusmo
LQ Newbie
 
Registered: Nov 2010
Location: Czech republic, Europe
Distribution: RedHat, CentOS, Ubuntu
Posts: 5

Rep: Reputation: 0
Editing grub does not work

I have exactly the same problem and it really does not necessarily need to solve. Can anyone help please?
 
  


Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
[SOLVED] Grub: If exists sdb, then boot sdb, else sda defaultyeti Linux - Desktop 6 06-28-2011 03:38 AM
[SOLVED] FC 10: RAID failure test: grub cannot find boot device jot Fedora 3 03-26-2009 10:11 AM
Ubuntu Raid 1, can't boot after Single Disk Failure elliotfuller Linux - General 7 06-05-2007 11:05 PM
Will not boot RAID drive after PS failure. webguyinternet Linux - Server 0 10-04-2006 03:59 PM
can't boot raid array after drive failure Rascale Linux - Hardware 4 02-12-2006 07:41 PM


All times are GMT -5. The time now is 12:32 PM.

Main Menu
Advertisement
My LQ
Write for LQ
LinuxQuestions.org is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
Syndicate
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
identi.ca: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration