Xen kernel panic - LVM volumes not accessible

Discussion in 'HOWTO-Related Questions' started by lmacka, Aug 20, 2012.

  1. lmacka

    lmacka New Member

    I have followed the howto here:
    http://www.howtoforge.com/virtualiz...aravirtualization-and-hardware-virtualization

    I'm trying to install on a Dell R720 with a hardware RAID5 configuration and 4 cores. The RAID's configured so I have a single ~3TB volume, /dev/sda

    I've followed the tutorial all the way to the point where I reboot into my new kernel. When booting, xen.gz appears and loads properly, then the kernel also appears to load but ends up in a kernel panic with the following output:


    ...
    dracut Warning: No root device "block:/dev/mapper/vg_cbcxen-lv_root" found
    dracut Warning: LVM vg_cbcxen/lv_swap not found
    dracut Warning: LVM vg_cbcxen/lv_root not found


    Obviously it's having problems finding my LVMs or a required driver isn't loading. I've searched the web but to no avail. Hoping someone here can point me in the right direction...

    My grub.conf is as follows:

    Code:
    default=0
    timeout=30
    splashimage=(hd0,0)/grub/splash.xpm.gz
    hiddenmenu
    title CentOS (2.6.32.57-2.el6xen.x86_64)
            root (hd0,0)
            kernel /xen.gz dom0_mem=1024M cpufreq=xen dom0_max_vcpus=4 dom0_vcpus_pin
            module /vmlinuz-2.6.32.57-2.el6xen.x86_64 ro root=/dev/mapper/vg_cbcxen-lv_root nomodeset rd_NO_LUKS rd_LVM_LV=vg_cbcxen/lv_swap LANG=en_US.UTF-8 rd_LVM_LV=vg_cbcxen/lv_root rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM
            module /initramfs-2.6.32.57-2.el6xen.x86_64.img
    title CentOS (2.6.32-279.el6.x86_64)
            root (hd0,0)
            kernel /vmlinuz-2.6.32-279.el6.x86_64 ro root=/dev/mapper/vg_cbcxen-lv_root nomodeset rd_NO_LUKS rd_LVM_LV=vg_cbcxen/lv_swap LANG=en_US.UTF-8 rd_LVM_LV=vg_cbcxen/lv_root rd_NO_MD SYSFONT=latarcyrheb-sun16 crashkernel=auto  KEYBOARDTYPE=pc KEYTABLE=us rd_NO_DM rhgb quiet
            initrd /initramfs-2.6.32-279.el6.x86_64.img
    
    Version and file info:
    Code:
    [[email protected] ~]# rpm -qa | grep xen
    xen-libs-4.1.3-1.el6.x86_64
    xen-runtime-4.1.3-1.el6.x86_64
    xen-4.1.3-1.el6.x86_64
    kernel-xen-2.6.32.57-2.x86_64
    kernel-xen-release-6-3.noarch
    xen-licenses-4.1.3-1.el6.x86_64
    xen-hypervisor-4.1.3-1.el6.x86_64
    xen-devel-4.1.3-1.el6.x86_64
    [[email protected] ~]# ls -l /boot/
    total 52801
    -rw-r--r--. 1 root root   101820 Jun 22 19:44 config-2.6.32-279.el6.x86_64
    -rw-r--r--  1 root root    95612 May 25 11:25 config-2.6.32.57-2.el6xen.x86_64
    drwxr-xr-x. 3 root root     1024 Aug 18 23:41 efi
    drwxr-xr-x. 2 root root     1024 Aug 20 22:13 grub
    -rw-r--r--. 1 root root 14822507 Aug 18 23:41 initramfs-2.6.32-279.el6.x86_64.img
    -rw-r--r--  1 root root 12620635 Aug 20 21:43 initramfs-2.6.32.57-2.el6xen.x86_64.img
    drwx------. 2 root root    12288 Aug 18 23:08 lost+found
    -rw-r--r--. 1 root root   179157 Jun 22 19:45 symvers-2.6.32-279.el6.x86_64.gz
    -rw-r--r--  1 root root   157712 May 25 11:25 symvers-2.6.32.57-2.el6xen.x86_64.gz
    -rw-r--r--. 1 root root  2341856 Jun 22 19:44 System.map-2.6.32-279.el6.x86_64
    -rw-r--r--  1 root root  2178713 May 25 11:25 System.map-2.6.32.57-2.el6xen.x86_64
    -rwxr-xr-x. 1 root root  3986608 Jun 22 19:44 vmlinuz-2.6.32-279.el6.x86_64
    -rw-r--r--  1 root root  3495856 May 25 11:25 vmlinuz-2.6.32.57-2.el6xen.x86_64
    -rw-r--r--. 1 root root   737584 Aug 11 12:08 xen-4.1.3.gz
    lrwxrwxrwx. 1 root root       12 Aug 18 23:56 xen-4.1.gz -> xen-4.1.3.gz
    lrwxrwxrwx. 1 root root       12 Aug 18 23:56 xen.gz -> xen-4.1.3.gz
    -rw-r--r--. 1 root root 13317834 Aug 11 12:08 xen-syms-4.1.3
    [[email protected] ~]# parted
    GNU Parted 2.1
    Using /dev/sda
    Welcome to GNU Parted! Type 'help' to view a list of commands.
    (parted) print all
    Model: DELL PERC H710 (scsi)
    Disk /dev/sda: 2999GB
    Sector size (logical/physical): 512B/512B
    Partition Table: gpt
    
    Number  Start   End     Size    File system  Name  Flags
     1      1049kB  525MB   524MB   ext4               boot
     2      525MB   2999GB  2998GB                     lvm
    
    
    Error: partition length of 5735235584 sectors exceeds the loop-partition-table-imposed maximum of 4294967295
    
    Model: Linux device-mapper (linear) (dm)
    Disk /dev/mapper/vg_cbcxen-lv_swap: 8305MB
    Sector size (logical/physical): 512B/512B
    Partition Table: loop
    
    Number  Start  End     Size    File system     Flags
     1      0.00B  8305MB  8305MB  linux-swap(v1)
    
    
    Model: Linux device-mapper (linear) (dm)
    Disk /dev/mapper/vg_cbcxen-lv_root: 53.7GB
    Sector size (logical/physical): 512B/512B
    Partition Table: loop
    
    Number  Start  End     Size    File system  Flags
     1      0.00B  53.7GB  53.7GB  ext4
    
    Note that I'm planning on shrinking that /home volume and setting up LVM based VMs.

    TIA for any assistance...
     
    Last edited: Aug 20, 2012
  2. lmacka

    lmacka New Member

    Further progressing down the track of trial and error, I thought the problem might be related to a lack of LVM support in the initramfs that the new kernel was loading, so I made my own with pretty much everything in it that could be used. Here's the command I used to do it after booting into my good kernel.

    Code:
    dracut --force -a 'base lvm kernel-modules dm rootfs-block' --add-drivers 'scsi_mod scsi_wait_scan ext4 megaraid_sas sd_mod ahci wmi dm_mirror dm_region_hash dm_log dm_mod tg3' --nomdadmconf --lvmconf -v /boot/initramfs-2.6.32.57-2.el6xen.x86_64.img 2.6.32.57-2.el6xen.x86_64
    It didn't work, but since there's a lack of examples around for this command I thought I'd post it anyway. I realize that there's some addition fluff in there that I don't need. Trial and error.

    So my initramfs definitely has LVM and Dell PERC driver support in it, must be a configuration issue.
    I'm almost out of ideas.... Help?
     
  3. lmacka

    lmacka New Member

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