Bug 490004

Summary:	Creation of mirrored logical volume with VG extent-size of 1K fails
Product:	Red Hat Enterprise Linux 4	Reporter:	Nate Straz <nstraz>
Component:	lvm2	Assignee:	Milan Broz <mbroz>
Status:	CLOSED ERRATA	QA Contact:	Cluster QE <mspqa-list>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	4.8	CC:	agk, cmarthal, dwysocha, edamato, heinzm, jbrassow, mbroz, prockai, pvrabec
Target Milestone:	rc
Target Release:	---
Hardware:	i386
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:	477040	Environment:
Last Closed:	2009-05-18 20:10:46 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:	477040
Bug Blocks:	490021

Description Nate Straz 2009-03-12 20:25:44 UTC

+++ This bug was initially created as a clone of Bug #477040 +++

Hitting this in 4.8 Beta too, cloning the 5.4 bug.  Can we get this in too?

+++ This bug was initially created as a clone of Bug #471565 +++

Usespace part, lvm2 need calculate properly sized log device

Description of problem:
Creation of a mirrored LV with disk log fails, if the VG extent-size is 1K (2K and bigger works as expected).


Version-Release number of selected component (if applicable):
$ lvm version
  LVM version:     2.02.32-RHEL5 (2008-03-04)
  Library version: 1.02.24 (2007-12-20)
  Driver version:  4.11.5 


How reproducible:
Create a volume group with extent size of 1K and a mirrored logical volume with a disk based mirror log.


Steps to Reproduce:
$ dd if=/dev/zero of=/test/image[1,2,3] bs=1024k count=128
$ losetup /dev/loop0 /test/image1
$ losetup /dev/loop1 /test/image2
$ losetup /dev/loop2 /test/image3
$ pvcreate /dev/loop[0,1,2]
  Physical volume "/dev/loop[0,1,2]" successfully created
$ vgcreate -s 1K vg_mirror_test /dev/loop0 /dev/loop1 /dev/loop2
  Volume group "vg_mirror_test" successfully created
$ lvcreate -L 64M -m 1 -n lv_mirror1 vg_mirror_test /dev/loop0 /dev/loop1 /dev/loop2:0-0
  /dev/cdrom: open failed: Read-only file system
 
No more output shown.

  
Actual results:
dmesg and /var/log/messages shows this:
 
===
Nov  4 17:43:17 nagtest-web1 lvm[16895]: Log device, 253:2, has failed.  
Nov  4 17:43:17 nagtest-web1 lvm[16895]: Device failure in vg_mirror_test-lv_mirror1
Nov  4 17:43:17 nagtest-web1 lvm[16895]: WARNING: dev_open(/etc/lvm/lvm.conf) called while suspended
Nov  4 17:43:16 nagtest-web1 kernel: attempt to access beyond end of device
Nov  4 17:43:22 nagtest-web1 kernel: dm-2: rw=16, want=3, limit=2
Nov  4 17:43:22 nagtest-web1 kernel: device-mapper: mirror log: Failed to read header on mirror log device, 253:2
Nov  4 17:43:22 nagtest-web1 kernel: attempt to access beyond end of device
Nov  4 17:43:22 nagtest-web1 kernel: dm-2: rw=17, want=3, limit=2
Nov  4 17:43:22 nagtest-web1 kernel: device-mapper: mirror log: Failed to write header on mirror log device, 253:2
Nov  4 17:43:22 nagtest-web1 kernel: device-mapper: raid1: log resume failed
Nov  4 17:43:22 nagtest-web1 kernel: attempt to access beyond end of device
Nov  4 17:43:22 nagtest-web1 kernel: dm-2: rw=17, want=3, limit=2
Nov  4 17:43:22 nagtest-web1 kernel: attempt to access beyond end of device
Nov  4 17:43:22 nagtest-web1 kernel: dm-2: rw=17, want=3, limit=2
Nov  4 17:43:22 nagtest-web1 kernel: attempt to access beyond end of device
===
'top' lists the kmirrord process with high cpu utilization:
PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
5541 root      20  -5     0    0    0 R 95.9  0.0  12:30.75 kmirrord
===
 
The errors continue forever ...
It seems that a 1K mirror log (because the size of the mirror log is equal to the size of the VG phsical extend) isn't big enough to hold the log information!


Expected results:
$ lvcreate -L 64M -m 1 -n lv_mirror1 vg_mirror_test /dev/loop0 /dev/loop1 /dev/loop2:0-0
  /dev/cdrom: open failed: Read-only file system
  Logical volume "lv_mirror1" created

--- Additional comment from mbroz on 2008-12-19 10:31:03 EDT ---

Fixed in upstream cvs in lvm2 2.02.44, planned for inclusion in RHEL5.4.

Comment 1 Milan Broz 2009-03-12 20:49:01 UTC

There are two parts, one is kernel part, which fixes log device constructor to check properly for log size and prevents "access beyond end of device".

Second is lvm2 part, which correctly calculates disk log size here.

Please clone that bug for kernel (I think that kernel part is more important here, should be easy patch).

I'll check how complicated is the lvm2 usespace part to backport...

Comment 4 Milan Broz 2009-03-24 21:19:41 UTC

Fixed in lvm2-2.02.42-5.el4

Comment 7 Corey Marthaler 2009-04-03 20:57:01 UTC

Fix verified in lvm2-2.02.42-5.el4.

SCENARIO - [create_mirror_on_1Kextent_vg]
Create a mirror on a VG with an extent size of only 1K
Recreating PVs/VG with smaller (1K) extent size
hayes-01: vgcreate -s 1K mirror_sanity /dev/etherd/e1.1p1 /dev/etherd/e1.1p2 /dev/etherd/e1.1p3 /dev/etherd/e1.1p4 /dev/etherd/e1.1p5
hayes-01: lvcreate -m 1 -n mirror_on_1Kextent_vg -L 20M mirror_sanity
Deactivating mirror mirror_on_1Kextent_vg... and removing
Restoring VG to default extent size

Comment 9 errata-xmlrpc 2009-05-18 20:10:46 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-2009-0967.html