1777000 – lvconvert or lvchange command needs to load dm-writecache module if not already loaded

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Bug 1777000 - lvconvert or lvchange command needs to load dm-writecache module if not already loaded

Summary: lvconvert or lvchange command needs to load dm-writecache module if not alrea...

Keywords:
Status:	CLOSED ERRATA
Alias:	None
Product:	Red Hat Enterprise Linux 8
Classification:	Red Hat
Component:	lvm2
Sub Component:
Version:	8.2
Hardware:	x86_64
OS:	Linux
Priority:	unspecified
Severity:	medium
Target Milestone:	rc
Target Release:	8.0
Assignee:	LVM and device-mapper development team
QA Contact:	cluster-qe@redhat.com
Docs Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+	depends on / blocked

Reported:	2019-11-26 17:10 UTC by Corey Marthaler
Modified:	2021-09-07 11:57 UTC (History)
CC List:	11 users (show)
Fixed In Version:	lvm2-2.03.07-1.el8
Doc Type:	If docs needed, set a value
Doc Text:
Clone Of:
Environment:
Last Closed:	2020-04-28 16:58:59 UTC
Type:	Bug
Target Upstream Version:
Embargoed:
Dependent Products:

Attachments	(Terms of Use)

Links
System	ID	Private	Priority	Status	Summary	Last Updated
Red Hat Issue Tracker	RHELPLAN-30632	0	None	None	None	2021-09-07 11:56:12 UTC
Red Hat Product Errata	RHEA-2020:1881	0	None	None	None	2020-04-28 16:59:15 UTC

Description Corey Marthaler 2019-11-26 17:10:14 UTC

Description of problem:

[root@hayes-02 ~]# lvcreate -L 1G -n origin seven /dev/sdi1
  Logical volume "origin" created.
[root@hayes-02 ~]# lvcreate -L 200M -n wpool seven /dev/sdk1
  Logical volume "wpool" created.


### Currently the dm-wc conversion requires the two above LVs to be inactive. Should the following conversion command do the modprobe (and auto activate) or should the lvchange do it?
[root@hayes-02 ~]# lvchange -an seven

[root@hayes-02 ~]# lvconvert --yes --type writecache --cachevol seven/wpool seven/origin
  Logical volume seven/origin now has write cache.
[root@hayes-02 ~]# lvs -a -o +devices
  LV              VG    Attr       LSize   Pool         Origin          Data%  Meta%  Move Log Cpy%Sync Convert Devices         
  origin          seven Cwi---C---   1.00g [wpool_cvol] [origin_wcorig]                                         origin_wcorig(0)
  [origin_wcorig] seven owi---C---   1.00g                                                                      /dev/sdi1(0)    
  [wpool_cvol]    seven Cwi---C--- 200.00m                                                                      /dev/sdk1(0)    

[root@hayes-02 ~]# lvchange -ay seven/origin
  Can't process LV seven/origin: writecache target support missing from kernel?

[root@hayes-02 ~]# modprobe dm-writecache
[root@hayes-02 ~]# lvchange -ay seven/origin
[root@hayes-02 ~]# lvs -a -o +devices
  LV              VG    Attr       LSize   Pool         Origin          Data%  Meta%  Move Log Cpy%Sync Convert Devices         
  origin          seven Cwi-a-C---   1.00g [wpool_cvol] [origin_wcorig]                                         origin_wcorig(0)
  [origin_wcorig] seven owi-aoC---   1.00g                                                                      /dev/sdi1(0)    
  [wpool_cvol]    seven Cwi-aoC--- 200.00m                                                                      /dev/sdk1(0)    


Version-Release number of selected component (if applicable):
kernel-4.18.0-151.el8    BUILT: Fri Nov 15 13:14:53 CST 2019
lvm2-2.03.06-0.2.el8    BUILT: Mon Nov 18 06:39:12 CST 2019
lvm2-libs-2.03.06-0.2.el8    BUILT: Mon Nov 18 06:39:12 CST 2019
lvm2-dbusd-2.03.06-0.2.el8    BUILT: Mon Nov 18 06:39:12 CST 2019
device-mapper-1.02.165-0.2.el8    BUILT: Mon Nov 18 06:39:12 CST 2019
device-mapper-libs-1.02.165-0.2.el8    BUILT: Mon Nov 18 06:39:12 CST 2019
device-mapper-event-1.02.165-0.2.el8    BUILT: Mon Nov 18 06:39:12 CST 2019
device-mapper-event-libs-1.02.165-0.2.el8    BUILT: Mon Nov 18 06:39:12 CST 2019
device-mapper-persistent-data-0.8.5-2.el8    BUILT: Wed Jun  5 10:28:04 CDT 2019


How reproducible:
Everytime

Comment 1 David Teigland 2019-11-26 17:23:06 UTC

pushed fix to master
https://sourceware.org/git/?p=lvm2.git;a=commitdiff;h=1c9b36618ec8357350ed4d83c807ae0bf27a12be

Comment 5 Corey Marthaler 2020-01-06 16:28:40 UTC

Fix verified in the latest rpms.

kernel-4.18.0-167.el8    BUILT: Sat Dec 14 19:43:52 CST 2019
lvm2-2.03.07-1.el8    BUILT: Mon Dec  2 00:09:32 CST 2019
lvm2-libs-2.03.07-1.el8    BUILT: Mon Dec  2 00:09:32 CST 2019
device-mapper-1.02.167-1.el8    BUILT: Mon Dec  2 00:09:32 CST 2019
device-mapper-libs-1.02.167-1.el8    BUILT: Mon Dec  2 00:09:32 CST 2019
device-mapper-event-1.02.167-1.el8    BUILT: Mon Dec  2 00:09:32 CST 2019
device-mapper-event-libs-1.02.167-1.el8    BUILT: Mon Dec  2 00:09:32 CST 2019


[root@hayes-02 ~]# lsmod | grep write

[root@hayes-02 ~]# vgcreate seven /dev/sd[ik]1
  Physical volume "/dev/sdi1" successfully created.
  Physical volume "/dev/sdk1" successfully created.
  Volume group "seven" successfully created
[root@hayes-02 ~]# lvcreate -L 1G -n origin seven /dev/sdi1
  Logical volume "origin" created.
[root@hayes-02 ~]# lvcreate -L 200M -n wpool seven /dev/sdk1
  Logical volume "wpool" created.
[root@hayes-02 ~]# lvchange -an seven
[root@hayes-02 ~]# lvconvert --yes --type writecache --cachevol seven/wpool seven/origin
  Logical volume seven/origin now has write cache.
[root@hayes-02 ~]# lvs -a -o +devices
  LV              VG    Attr       LSize   Pool         Origin          Data%  Meta% Devices         
  origin          seven Cwi---C---   1.00g [wpool_cvol] [origin_wcorig]              origin_wcorig(0)
  [origin_wcorig] seven owi---C---   1.00g                                           /dev/sdi1(0)    
  [wpool_cvol]    seven Cwi---C--- 200.00m                                           /dev/sdk1(0)    


[root@hayes-02 ~]# lvchange -ay seven/origin

Jan  6 10:23:47 hayes-02 kernel: TECH PREVIEW: DM writecache may not be fully supported.#012Please review provided documentation for limitations.

[root@hayes-02 ~]# lvs -a -o +devices
  LV              VG    Attr       LSize   Pool         Origin          Data%  Meta% Devices         
  origin          seven Cwi-a-C---   1.00g [wpool_cvol] [origin_wcorig]              origin_wcorig(0)
  [origin_wcorig] seven owi-aoC---   1.00g                                           /dev/sdi1(0)    
  [wpool_cvol]    seven Cwi-aoC--- 200.00m                                           /dev/sdk1(0)    

[root@hayes-02 ~]# lsmod | grep write
dm_writecache          36864  1
dm_mod                151552  11 dm_multipath,dm_writecache

Comment 7 errata-xmlrpc 2020-04-28 16:58:59 UTC

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.

https://access.redhat.com/errata/RHEA-2020:1881

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