Comment 0 for bug 1874641

#lvconvert --type writecache --cachesettings 'low_watermark=0 high_watermark=10 writeback_jobs=2048' --cachevol cache ssd
  WARNING: Unrecognised segment type writecache
  Invalid argument for --type: writecache
  Error during parsing of command line.

lvm2 package was build without key --with-writecache=internal

#lvm version
  LVM version: 2.03.07(2) (2019-11-30)
  Library version: 1.02.167 (2019-11-30)
  Driver version: 4.41.0
  Configuration: ./configure --build=x86_64-linux-gnu --prefix=/usr --includedir=${prefix}/include --mandir=${prefix}/share/man --infodir=${prefix}/share/info --sysconfdir=/etc --localstatedir=/var --disable-silent-rules --libdir=${prefix}/lib/x86_64-linux-gnu --libexecdir=${prefix}/lib/x86_64-linux-gnu --runstatedir=/run --disable-maintainer-mode --disable-dependency-tracking --exec-prefix= --bindir=/bin --libdir=/lib/x86_64-linux-gnu --sbindir=/sbin --with-usrlibdir=/usr/lib/x86_64-linux-gnu --with-optimisation=-O2 --with-cache=internal --with-device-uid=0 --with-device-gid=6 --with-device-mode=0660 --with-default-pid-dir=/run --with-default-run-dir=/run/lvm --with-default-locking-dir=/run/lock/lvm --with-thin=internal --with-thin-check=/usr/sbin/thin_check --with-thin-dump=/usr/sbin/thin_dump --with-thin-repair=/usr/sbin/thin_repair --enable-applib --enable-blkid_wiping --enable-cmdlib --enable-dmeventd --enable-dbus-service --enable-lvmlockd-dlm --enable-lvmlockd-sanlock --enable-lvmpolld --enable-notify-dbus --enable-pkgconfig --enable-readline --enable-udev_rules --enable-udev_sync

#lsmod | grep dm_writecache
dm_writecache 36864 0

#lsb_release -rd
Description: Ubuntu 20.04 LTS
Release: 20.04

#apt-cache policy lvm2
lvm2:
  Installed: 2.03.07-1ubuntu1
  Candidate: 2.03.07-1ubuntu1
  Version table:
 *** 2.03.07-1ubuntu1 500
        500 http://ua.archive.ubuntu.com/ubuntu focal/main amd64 Packages
        100 /var/lib/dpkg/status

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: lvm2 2.03.07-1ubuntu1
ProcVersionSignature: Ubuntu 5.4.0-26.30-generic 5.4.30
Uname: Linux 5.4.0-26-generic x86_64
ApportVersion: 2.20.11-0ubuntu27
Architecture: amd64
CasperMD5CheckResult: pass
Date: Fri Apr 24 07:48:49 2020
InstallationDate: Installed on 2020-04-23 (0 days ago)
InstallationMedia: Ubuntu-Server 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: lvm2
UpgradeStatus: No upgrade log present (probably fresh install)