Bug 247444 - LVM2 needs method to see which metadata areas are on which PVs
Summary: LVM2 needs method to see which metadata areas are on which PVs
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux 4
Classification: Red Hat
Component: lvm2
Version: 4.5
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
: ---
Assignee: Milan Broz
QA Contact: Corey Marthaler
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2007-07-09 11:08 UTC by Bryn M. Reeves
Modified: 2018-10-19 19:54 UTC (History)
7 users (show)

Fixed In Version: RHBA-2007-0753
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2007-11-15 15:58:40 UTC
Target Upstream Version:
Embargoed:


Attachments (Terms of Use)


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHBA-2007:0753 0 normal SHIPPED_LIVE lvm2 bug fix and enhancement update 2007-11-14 16:56:08 UTC

Description Bryn M. Reeves 2007-07-09 11:08:57 UTC
Description of problem:
When using large numbers of physical volumes it is recommended to create some
with --metadatacopies=0 to improve tool performance. The vgdisplay command will
show how many metadata copies exist in the volume group, but not which PVs they
reside on.

Currently this can only be determined by running pvdisplay for each PV in the
VG. For a metadata-containing PV the output will be like:


# pvdisplay /dev/loop0
  --- Physical volume ---
  PV Name               /dev/loop0
  VG Name               t0
  PV Size               64.00 MB / not usable 4.00 MB
  Allocatable           yes 
  PE Size (KByte)       4096
  Total PE              15
  Free PE               15
  Allocated PE          0
  PV UUID               3CD0to-e2vD-adwE-1GS4-Icyl-3lPd-WdcE4U

Whereas a non-metadata containing PV that is a member of a VG will look like an
unused PV:

# pvdisplay /dev/loop1
  --- NEW Physical volume ---
  PV Name               /dev/loop1
  VG Name               
  PV Size               64.00 MB
  Allocatable           NO
  PE Size (KByte)       0
  Total PE              0
  Free PE               0
  Allocated PE          0
  PV UUID               drpyTg-wsM9-LODi-enmN-c02m-UiG8-ZfmQim

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. Try to determine which PV contains the MDA with LVM2 tools
  
Actual results:
LVM2 tools cannot directly reveal this information

Expected results:
LVM2 tools can directly reveal this information

Additional info:

Comment 1 Bryn M. Reeves 2007-07-09 16:09:47 UTC
Upstream commit adding support for vg_mda_count and pv_mda_count to reporting tools:

http://sourceware.org/cgi-bin/cvsweb.cgi/LVM2/WHATS_NEW.diff?cvsroot=lvm2&r1=1.648&r2=1.649

Comment 4 RHEL Program Management 2007-07-13 14:24:32 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 7 Milan Broz 2007-08-03 10:05:59 UTC
*** Bug 202886 has been marked as a duplicate of this bug. ***

Comment 14 errata-xmlrpc 2007-11-15 15:58:40 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 the 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-2007-0753.html



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