Bug 2095516

Summary:	writecache: display block size from lvs
Product:	Red Hat Enterprise Linux 8	Reporter:	David Teigland <teigland>
Component:	lvm2	Assignee:	David Teigland <teigland>
lvm2 sub component:	Cache Logical Volumes	QA Contact:	cluster-qe <cluster-qe>
Status:	CLOSED ERRATA	Docs Contact:
Severity:	unspecified
Priority:	unspecified	CC:	agk, cmarthal, heinzm, jbrassow, mcsontos, msnitzer, prajnoha, zkabelac
Version:	8.0	Keywords:	Triaged
Target Milestone:	rc
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:	lvm2-2.03.14-4.el8	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2022-11-08 10:55:29 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description David Teigland 2022-06-09 20:14:40 UTC

Description of problem:

lvs was missing the ability to display writecache block size.

now possible with lvs -o writecache_block_size

fix in main branch:
https://sourceware.org/git/?p=lvm2.git;a=commit;h=ac1f4bbbfd4c5f1387c3e0607f7d556409e7a4b4

Version-Release number of selected component (if applicable):


How reproducible:


Steps to Reproduce:
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Actual results:


Expected results:


Additional info:

Comment 4 Corey Marthaler 2022-07-15 18:45:47 UTC

Marking Verified:Tested

# Before fix
lvm2-2.03.14-3.el8    BUILT: Tue Jan  4 14:54:16 CST 2022

[root@hayes-02 ~]# lvs -o writecache_block_size
  [...]
  Unrecognised field: writecache_block_size



# After fix
lvm2-2.03.14-4.el8    BUILT: Wed Jun 15 17:14:34 CDT 2022

[root@hayes-01 ~]# lvs -o writecache_block_size
  WCacheBlkSize
           4096

Comment 7 Corey Marthaler 2022-07-28 16:10:53 UTC

Fix verified in the latest kernel/lvm2 rpms as well.


kernel-4.18.0-411.el8    BUILT: Wed Jul 20 18:42:42 CDT 2022
lvm2-2.03.14-5.el8    BUILT: Thu Jul 14 09:23:13 CDT 2022
lvm2-libs-2.03.14-5.el8    BUILT: Thu Jul 14 09:23:13 CDT 2022


SCENARIO - [display_writecache]
Create a writecache volume and then display it a couple ways

*** Writecache info for this scenario ***
*  origin (slow):  /dev/sdh1
*  pool (fast):    /dev/sde1
************************************

Adding "slow" and "fast" tags to corresponding pvs
Create origin (slow) volume
lvcreate --yes --wipesignatures y  -L 4G -n display_writecache writecache_sanity @slow

Create writecache cvol (fast) volumes
lvcreate --yes  -L 4G -n pool writecache_sanity @fast

Deactivate *ONLY* fast pool before conversion to write cache (SEE bug 1185347)
Create writecached volume by combining the cache pool (fast) and origin (slow) volumes
lvconvert --yes --type writecache --cachesettings 'low_watermark=35 high_watermark=82 writeback_jobs=2386 autocommit_blocks=2767 autocommit_time=1617' --cachevol writecache_sanity/pool writecache_sanity/display_writecache
Display cache volume using lvdisplay
  --- Logical volume ---
  LV Path                /dev/writecache_sanity/display_writecache
  LV Name                display_writecache
  VG Name                writecache_sanity
  LV UUID                OraF4p-z1tl-yqp0-wNdM-8RM8-LpNO-SZuObX
  LV Write Access        read/write
  LV Creation host, time hayes-01.lab.msp.redhat.com, 2022-07-28 11:09:45 -0500
  LV Status              available
  # open                 0
  LV Size                4.00 GiB
  Current LE             1024
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:0
   

Display cache using lvs
  LV                 VG                Attr       LSize Pool        Origin                      Data%  Meta%  Move Log Cpy%Sync Convert Devices                     
  display_writecache writecache_sanity Cwi-a-C--- 4.00g [pool_cvol] [display_writecache_wcorig] 0.00                                    display_writecache_wcorig(0)

Display cache using lvscan
  ACTIVE            '/dev/writecache_sanity/display_writecache' [4.00 GiB] inherit


Display -am (all mapping) for both cache origin and pool volumes using lvdisplay (bug 1533334)
Attribute regression checks for bug 1789582
        display_writecache: Cwi-a-C---
        display_writecache_wcorig: owi-aoC---
        pool_cvol: Cwi-aoC---
data percent: 0

Display write cache block size
  WCacheBlkSize
           4096

Uncaching cache origin (lvconvert --yes --uncache writecache_sanity/display_writecache) from cache origin
Removing cache origin volume writecache_sanity/display_writecache
lvremove -f /dev/writecache_sanity/display_writecache

Comment 9 errata-xmlrpc 2022-11-08 10:55:29 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 (lvm2 bug fix and enhancement update), 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/RHBA-2022:7792