Bug 426269

+++ This bug was initially created as a clone of Bug #360111 +++

Description of problem:

When triggering a kernel crash, kdump fails to find my logical volumes and then
doesn't save the crashdump.

Version-Release number of selected component (if applicable):

kernel 2.6.18-8.1.15.el5
kexec-tools-1.101-164.el5
lvm2-2.02.16-3.el5

How reproducible:

100%

Steps to Reproduce:
1. install a rhel5 system with all filesystems on lvm, using the follwing
anaconda script:
 clearpart --all --initlabel
 part /boot --fstype ext3 --size=128
 part pv.100000 --size=0 --grow
 volgroup rootvg --pesize=32768 pv.100000
 logvol /var --fstype ext3 --name=varlv --vgname=rootvg --size=3072
 logvol swap --fstype swap --name=swaplv --vgname=rootvg --size=2048
 logvol / --fstype ext3 --name=rootlv --vgname=rootvg --size=5120
 logvol /local --fstype ext3 --name=locallv --vgname=rootvg --size=1024

2. configure kdump to default to shell
3. crash it with echo c > /proc/sysrq-trigger
  
Actual results:

Fails to get a dump because during kdump initialization it can't find
/dev/mapper/-varlv, /dev/mapper/-swaplv, /dev/mapper/-rootlv.


Expected results:

It should find /dev/mapper/rootvg-varlv, /dev/mapper/rootvg-swaplv, etc.. and
give me a crash dump.

Additional info:

I checked the "init" script in the kdump initrd, and found the following section
 which seems to contain the bug:

for i in `lvm lvs | awk '{ if (NR > 1) print $1}'`

# loops over the following LV's: crashlv locallv projects rootlv swaplv varlv
machete.

do
   VGRP=`lvm lvs | grep $i | cut -d" " -f4`

Ouch! it's cut'ing on number of spaces. Only one of my LV's has long enough
names to only have 3 spaces in the output before the VG-name:

# for i in crashlv locallv machete projects rootlv swaplv varlv  ; do lvm lvs |
grep $i  ; done
  crashlv  rootvg -wi-ao  4.00G                              
  locallv  rootvg -wi-ao  1.00G                              
  machete  rootvg -wi-ao  9.78G                              
  projects rootvg -wi-ao 19.53G    # This is my only match!                   
  rootlv   rootvg -wi-ao  5.00G                              
  swaplv   rootvg -wi-ao  2.00G                              
  varlv    rootvg -wi-ao  3.00G          

A much better command for finding the VG-name would be:

   VGRP=`lvm lvs | grep $i | awk '{print $2}'`


# for i in crashlv locallv machete projects rootlv swaplv varlv  ; do lvm lvs |
grep $i | cut -d" " -f4 ; done



rootvg



# for i in crashlv locallv machete projects rootlv swaplv varlv  ; do lvm lvs |
grep $i | awk '{print $2}' ; done
rootvg
rootvg
rootvg
rootvg
rootvg
rootvg
rootvg

-- Additional comment from mykleb.com on 2007-10-31 09:24 EST --
Created an attachment (id=244531)
use awk instead of cut to find volume group