On Fri, May 8, 2009 at 2:30 PM, Rudi Ahlers rudiahlers@gmail.com wrote:

Hi all,

One of our Dell servers has failed badly, and one of the domU's has been corrupted in the process. It boots up to a point and then gives me a kernel panic:

Loading dm-zero.ko module Loading dm-snapshot.ko module Scanning and configuring dmraid supported devices Scanning logical volumes Reading all physical volumes. This may take a while... No volume groups found Activating logical volumes Volume group "VolGroup00" not found Creating root device. Mounting root filesystem. mount: could not find filesystem '/dev/root' Setting up other filesystems. Setting up new root fs setuproot: moving /dev failed: No such file or directory no fstab.sys, mounting internal defaults setuproot: error mounting /proc: No such file or directory setuproot: error mounting /sys: No such file or directory Switching to new root and running init. unmounting old /dev unmounting old /proc unmounting old /sys switchroot: mount failed: No such file or directory Kernel panic - not syncing: Attempted to kill init!

It shows up as a Zombie:

[root@xen ~]# xm list Name ID Mem(MiB) VCPUs State Time(s) Domain-0 0 1439 1 r----- 329.0 Zombie-hfserver2 15 1024 1 ----c- 0.5 hfdns02 10 519 2 r----- 1552.8

I can't mount either:

root@xen ~]# mount /dev/data/hf hfdns02 hfserver2 [root@xen ~]# mount /dev/data/hfserver2 /mnt/cpanel/ mount: you must specify the filesystem type [root@xen ~]# mount -o loop /dev/data/hfserver2 /mnt/cpanel/ mount: you must specify the filesystem type

Here's the output of the LVM partitions:

[root@xen ~]# lvscan ACTIVE '/dev/data/cpanel002' [100.00 GB] inherit ACTIVE '/dev/data/windows2003_web' [30.00 GB] inherit ACTIVE '/dev/data/storage' [50.00 GB] inherit ACTIVE Original '/dev/data/hfserver2' [30.00 GB] inherit ACTIVE '/dev/data/hfdns02' [30.00 GB] inherit ACTIVE '/dev/data/pluto' [30.00 GB] inherit ACTIVE Snapshot '/dev/data/pluto_s' [30.00 GB] inherit ACTIVE '/dev/system/root' [39.06 GB] inherit ACTIVE '/dev/system/swap' [9.75 GB] inherit [root@xen ~]# vgscan Reading all physical volumes. This may take a while... Found volume group "data" using metadata type lvm2 Found volume group "system" using metadata type lvm2 [root@xen ~]#

Does anyone know how to fix a LVM like this?

--

Here's what I've done so far:

[root@xen ~]# losetup /dev/loop4 /dev/data/hfserver2

# This mounts the LVM partition as imaginary physical to /dev/loop4 # data is the virtual group (VG) name

[root@xen ~]# kpartx -va /dev/loop4 add map loop4p1 : 0 208782 linear /dev/loop4 63 add map loop4p2 : 0 62701695 linear /dev/loop4 208845

# This creates a device map with partitions in /dev/data/hfserver in /dev/mapper

[root@xen ~]# vgscan Reading all physical volumes. This may take a while... Found volume group "VolGroup00" using metadata type lvm2 Found volume group "data" using metadata type lvm2 Found volume group "system" using metadata type lvm2

[root@xen ~]# lvscan inactive '/dev/VolGroup00/LogVol00' [27.94 GB] inherit inactive '/dev/VolGroup00/LogVol01' [1.94 GB] inherit ACTIVE '/dev/data/cpanel002' [100.00 GB] inherit ACTIVE '/dev/data/windows2003_web' [30.00 GB] inherit ACTIVE '/dev/data/storage' [50.00 GB] inherit ACTIVE Original '/dev/data/hfserver2' [30.00 GB] inherit ACTIVE '/dev/data/hfdns02' [30.00 GB] inherit ACTIVE '/dev/data/pluto' [30.00 GB] inherit ACTIVE Snapshot '/dev/data/pluto_s' [30.00 GB] inherit ACTIVE '/dev/system/root' [39.06 GB] inherit ACTIVE '/dev/system/swap' [9.75 GB] inherit

[root@xen ~]# lvchange -ay VolGroup00 [root@xen ~]# lvscan ACTIVE '/dev/VolGroup00/LogVol00' [27.94 GB] inherit ACTIVE '/dev/VolGroup00/LogVol01' [1.94 GB] inherit ACTIVE '/dev/data/cpanel002' [100.00 GB] inherit ACTIVE '/dev/data/windows2003_web' [30.00 GB] inherit ACTIVE '/dev/data/storage' [50.00 GB] inherit ACTIVE Original '/dev/data/hfserver2' [30.00 GB] inherit ACTIVE '/dev/data/hfdns02' [30.00 GB] inherit ACTIVE '/dev/data/pluto' [30.00 GB] inherit ACTIVE Snapshot '/dev/data/pluto_s' [30.00 GB] inherit ACTIVE '/dev/system/root' [39.06 GB] inherit ACTIVE '/dev/system/swap' [9.75 GB] inherit

[root@xen ~]# e2fsck /dev/VolGroup00/LogVol00 e2fsck 1.39 (29-May-2006) /dev/VolGroup00/LogVol00: clean, 631982/7325696 files, 4512772/7323648 blocks

At first it found a whole lot of damages inodes which I repaired.

Then, I reversed the process:

[root@xen ~]# lvchange -an VolGroup00 [root@xen ~]# lvscan inactive '/dev/VolGroup00/LogVol00' [27.94 GB] inherit inactive '/dev/VolGroup00/LogVol01' [1.94 GB] inherit ACTIVE '/dev/data/cpanel002' [100.00 GB] inherit ACTIVE '/dev/data/windows2003_web' [30.00 GB] inherit ACTIVE '/dev/data/storage' [50.00 GB] inherit ACTIVE Original '/dev/data/hfserver2' [30.00 GB] inherit ACTIVE '/dev/data/hfdns02' [30.00 GB] inherit ACTIVE '/dev/data/pluto' [30.00 GB] inherit ACTIVE Snapshot '/dev/data/pluto_s' [30.00 GB] inherit ACTIVE '/dev/system/root' [39.06 GB] inherit ACTIVE '/dev/system/swap' [9.75 GB] inherit

[root@xen ~]# vgchange -an VolGroup00 0 logical volume(s) in volume group "VolGroup00" now active [root@xen ~]# kpartx -d /dev/loop4 [root@xen ~]# losetup -d /dev/loop4 [root@xen ~]#

[root@xen ~]# xm create -c /etc/xen/hfserver2

And then it dies:

Reading all physical volumes. This may take a while... Found volume group "VolGroup00" using metadata type lvm2 Activating logical volumes 2 logical volume(s) in volume group "VolGroup00" now active Creating root device. Mounting root filesystem. kjournald starting. Commit interval 5 seconds EXT3-fs: mounted filesystem with ordered data mode. Setting up other filesystems. Setting up new root fs no fstab.sys, mounting internal defaults Switching to new root and running init. unmounting old /dev unmounting old /proc unmounting old /sys exec of init (/sbin/init) failed!!!: No such file or directory Kernel panic - not syncing: Attempted to kill init! [root@xen ~]#