Bug 823918

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This request was erroneously removed from consideration in Red Hat Enterprise Linux 6.4, which is currently under development.  This request will be evaluated for inclusion in Red Hat Enterprise Linux 6.4.

This should have been fixed by c731bb1ee13565763cc1ac77ed1a01ccea0337ac.

This seems not to work as expected:

(10:05:53) [root@r6-node01:~]$ vgcreate vg /dev/sda1 /dev/sdb1
  Volume group "vg" successfully created
(10:06:39) [root@r6-node01:~]$ lvcreate -l50%FREE vg -n lv
  Logical volume "lv" created
(10:06:46) [root@r6-node01:~]$ lvconvert -m1 --alloc anywhere --corelog vg/lv
  vg/lv: Converted: 0.0%
  vg/lv: Converted: 6.6%
  vg/lv: Converted: 13.3%

from another console : 
(10:06:28) [root@r6-node01:~]$ /etc/init.d/lvm2-lvmetad stop
Signaling LVM metadata daemon to exit:                     [  OK  ]

back to the main console:


  Volume group "vg" not found
(10:07:36) [root@r6-node01:~]$ 

(10:07:36) [root@r6-node01:~]$ lvs
  WARNING: Failed to connect to lvmetad: No such file or directory. Falling back to internal scanning.
  LV      VG       Attr      LSize Pool Origin Data%  Move Log Cpy%Sync Convert
  lv_root VolGroup -wi-ao--- 7.54g                                             
  lv_swap VolGroup -wi-ao--- 1.97g                                             
  lv      vg       mwi-a-m-- 9.99g                                30.73        


But sync seemed to have continued;

:08:54) [root@r6-node01:~]$ lvs
  WARNING: Failed to connect to lvmetad: No such file or directory. Falling back to internal scanning.
  LV      VG       Attr      LSize Pool Origin Data%  Move Log Cpy%Sync Convert
  lv_root VolGroup -wi-ao--- 7.54g                                             
  lv_swap VolGroup -wi-ao--- 1.97g                                             
  lv      vg       mwi-a-m-- 9.99g                                37.45    

(10:09:36) [root@r6-node01:~]$ lvs -a -o +devices
  WARNING: Failed to connect to lvmetad: No such file or directory. Falling back to internal scanning.
  LV            VG       Attr      LSize Pool Origin Data%  Move Log Cpy%Sync Convert Devices                      
  lv_root       VolGroup -wi-ao--- 7.54g                                              /dev/vda2(0)                 
  lv_swap       VolGroup -wi-ao--- 1.97g                                              /dev/vda2(1930)              
  lv            vg       mwi-a-m-- 9.99g                                39.29         lv_mimage_0(0),lv_mimage_1(0)
  [lv_mimage_0] vg       Iwi-aom-- 9.99g                                              /dev/sda1(0)                 
  [lv_mimage_1] vg       Iwi-aom-- 9.99g                                              /dev/sdb1(0)

Just for clarity what happened on the console running lvconvert:

(10:06:46) [root@r6-node01:~]$ lvconvert -m1 --alloc anywhere --corelog vg/lv
  vg/lv: Converted: 0.0%
  vg/lv: Converted: 6.6%
  vg/lv: Converted: 13.3%

  Volume group "vg" not found
(10:07:36) [root@r6-node01:~]$

Yes, this is a known problem, but different from the segfault. A running LVM process can't switch over between lvmetad and non-lvmetad mode of operation on the fly. This might actually be a problem (especially for pvmove), but is certainly not a segfault as the bug title says. I suggest a new bug (targeted for 6.5) is created for the ability to fall back to non-lvmetad operation on the fly and this one is kept for the segfault (which was a somewhat different problem).

the lvcreate does not segfault anymore, it just returns back to prompt with the message Volume group "vg_name" not found.

The converting process keeps going on in the background. 

Since this is not related to segmentation fault anymore a new BZ will be opened describing this situation. 

Verified that there is no segfault with:

lvm2-2.02.98-6.el6.x86_64
lvm2-libs-2.02.98-6.el6.x86_64
lvm2-devel-2.02.98-6.el6.x86_64
lvm2-debuginfo-2.02.98-6.el6.x86_64

Created a BZ for 6.5 (Bug 891271) mentioning the issue with switching over (or rather not switching over)

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHBA-2013-0501.html