Bug 247448

Summary: LVM2 allows final MDA to be removed from a VG
Product: Red Hat Enterprise Linux 4 Reporter: Bryn M. Reeves <bmr>
Component: lvm2Assignee: Bryn M. Reeves <bmr>
Status: CLOSED ERRATA QA Contact: Corey Marthaler <cmarthal>
Severity: high Docs Contact:
Priority: high    
Version: 4.5CC: agk, ahecox, dmair, dwysocha, jbrassow, mbroz, prockai, tao
Target Milestone: ---   
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: RHBA-2008-0776 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: 2008-07-24 20:07:19 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 461306    
Attachments:
Description Flags
rfc patch adding checking for final MDA removal
none
create format instance for orphan volume groups
none
Make vgreduce use vg_split_mdas none

Description Bryn M. Reeves 2007-07-09 11:21:26 UTC 
Description of problem:
LVM2 permits PVs to be created with 0 or more metadata areas. Creating volume
groups with less MDAs than PVs improves tool performance for VGs with large
numbers of PVs.

Currently the tools permit the last MDA to be removed from a VG with no warning,
causing the VG to suddenly "disappear". 

Version-Release number of selected component (if applicable):
lvm2-2.02.21-5.el4, lvm2-2.02.24-1.fc7, lvm2 CVS 20070707.

How reproducible:
100%

Steps to Reproduce:
1. Create a volume group with #MDAS < #PVs:
pvcreate --metadatacopies=1 /dev/loop0
pvcreate --metadatacopies=0 /dev/loop1
vgcreate t0 /dev/loop0 /dev/loop1

2. Attempt to remove the PV that contains the MDA
vgreduce t0 /dev/loop0
 
Actual results:
# vgreduce t0 /dev/loop0
  Removed "/dev/loop0" from volume group "t0"
# vgs
  No volume groups found



Expected results:
# vgreduce t0 /dev/loop0
  Can't remove final metadata area on physical volume "/dev/loop0" from volume
group "t0"


Additional info:
Comment 1 Bryn M. Reeves 2007-07-09 12:48:15 UTC 
Created attachment 158763 [details]
rfc patch adding checking for final MDA removal
Comment 2 Bryn M. Reeves 2007-11-05 10:45:22 UTC 
Now the is_orphan_vg() patches are upstream this should be addressed by the
per-format type orphan support & using vg_split_mdas() to enforce the MDA checking.
Comment 3 Bryn M. Reeves 2008-03-20 22:33:44 UTC 
Created attachment 298754 [details]
create format instance for orphan volume groups

Make _vg_read_orphans create a format instance when reading orphan VGs.
Comment 4 Bryn M. Reeves 2008-03-20 22:34:43 UTC 
Created attachment 298755 [details]
Make vgreduce use vg_split_mdas

Make vgreduce use vg_split_mdas so we don't leave a VG with no MDAs at all.
Comment 9 RHEL Program Management 2008-04-02 12:38:44 UTC 
This request was evaluated by Red Hat Product Management for inclusion in a Red
Hat Enterprise Linux maintenance release.  Product Management has requested
further review of this request by Red Hat Engineering, for potential
inclusion in a Red Hat Enterprise Linux Update release for currently deployed
products.  This request is not yet committed for inclusion in an Update
release.
Comment 16 Corey Marthaler 2008-06-27 21:19:37 UTC 
Fix verified in lvm2-2.02.37-3.el4.
Comment 18 errata-xmlrpc 2008-07-24 20:07:19 UTC 
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on therefore solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.

http://rhn.redhat.com/errata/RHBA-2008-0776.html