System start aborts with "Couldn't find device with uuid" with LVM data on MD device
This document (7004113) is provided subject to the disclaimer at the end of this document.
Environment
SUSE Linux Enterprise Desktop 11
SUSE Linux Enterprise Desktop 10 Service Pack 2
SUSE Linux Enterprise Server 11
SUSE Linux Enterprise Server 10 Service Pack 2
Situation
After the initial installation a kernel based software RAID device was created with YaST2 and formatted with LVM data. After the volume group got extended the system reports on reboot:
Couldn't find device with uuid" v2PqTb-ai9D-FgB9-jELP-4uTs-FTsN-eVwTt1
and fails to start successfull.
Resolution
The file /etc/mdadm.conf is missing in the initrd to initialize the md based RAID. As the initialization of md devices takes place at a later point LVM is not able to find the specified UUID with the extends it got assigned with the md device. Please update to mkinitrd to 1.2-106.83 and lvm2 to 2.02.17-7 or later.
Copy the existing initrd to a temporary location, unpack it, copy /etc/mdadm.conf to the folder etc of the unpacked initrd, create a new gzip'ed cpio archive of it and move the initrd back to /boot.
Detailed workaround:
-
Create a temporary folder
'mkdir /tmp/initrd'
-
Run the command:
' mkinitrd -f "lvm2 md" '
to create an initrd with lvm2 and md support.
-
copy initrd to folder and change directory:
'cp /boot/initrd-2.6.27.25-0.1-pae /tmp/initrd'
'cd /tmp/initrd'
-
rename the initrd to a gzip'ed file:
'mv initrd-2.6.27.25-0.1-pae initrd-2.6.27.25-0.1-pae.gz'
-
unpack the initrd:
'gunzip initrd-2.6.27.25-0.1-pae.gz && cpio -i -d < initrd-2.6.27.25-0.1-pae'
-
delete the extracted file:
'rm initrd-2.6.27.25-0.1-pae'
-
copy /etc/mdadm.conf to extracted initrd
'cp /etc/mdadm.conf /tmp/initrd/etc/'
-
create a new archive:
' find . -print | cpio -o -Hnewc | gzip > /boot/initrd-2.6.27.25-0.1-pae.new'
This will create the archive and a new initrd in /boot beside the existing one.
-
Edit /boot/grub/menu.lst and change
initrd /initrd-2.6.27.25-0.1-pae
to
# initrd /initrd-2.6.27.25-0.1-pae
initrd /initrd-2.6.27.25-0.1-pae.new
so the original line is kept as backup.
-
reboot.
Additional Information
If the md device gets started using the command:
mdadm --create /dev/mdX --level=1 --raid-devices=2 /dev/sd[XY]z
this will not create a /etc/mdadm.conf file automatically. A config written by YaST2 usually contains information like this:
mdadm --create /dev/mdX --level=1 --raid-devices=2 /dev/sd[XY]z
this will not create a /etc/mdadm.conf file automatically. A config written by YaST2 usually contains information like this:
DEVICE partitions
ARRAY /dev/mdX level=raidY UUID=
To get the UUID for the md device run the command
mdadm -E /dev/sd[XY]z
against the RAID devices, like:
linux-zduj:~ # mdadm -E /dev/sd[bc]1 | grep UUID
UUID : 9102301d:c0764c48:07f45e96:8dddb797
UUID : 9102301d:c0764c48:07f45e96:8dddb797
UUID : 9102301d:c0764c48:07f45e96:8dddb797
UUID : 9102301d:c0764c48:07f45e96:8dddb797
So the file should look like:
DEVICE partitions
ARRAY /dev/md0 level=raid1 UUID=9102301d:c0764c48:07f45e96:8dddb797
DEVICE partitions
ARRAY /dev/md0 level=raid1 UUID=9102301d:c0764c48:07f45e96:8dddb797
The permissions for /etc/mdadm.conf are
linux-zduj:~ # ls -l /etc/mdadm.conf
-rw-r--r-- 1 root root 86 2009-08-04 17:44 /etc/mdadm.conf
-rw-r--r-- 1 root root 86 2009-08-04 17:44 /etc/mdadm.conf
Disclaimer
This Support Knowledgebase provides a valuable tool for SUSE customers and parties interested in our products and solutions to acquire information, ideas and learn from one another. Materials are provided for informational, personal or non-commercial use within your organization and are presented "AS IS" WITHOUT WARRANTY OF ANY KIND.
- Document ID:7004113
- Creation Date: 06-Aug-2009
- Modified Date:28-Sep-2022
-
- SUSE Linux Enterprise Desktop
- SUSE Linux Enterprise Server
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