era_invalidate: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/sbin/era_invalidate - from package: device-mapper-persistent-data
/usr/sbin/era_invalidate - from package: device-mapper-persistent-data

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/sbin/era_invalidate - from package: thin-provisioning-tools

You may install the required package with command apt-get install {package}

Error in other languages:
era_invalidate: bevel nie gevind nie
era_invalidate: comandă negăsită
era_invalidate: comando não encontrado
era_invalidate: commande introuvable
era_invalidate: command not found
era_invalidate: käsku ei ole
era_invalidate: không tìm thấy lệnh
era_invalidate: komanda nerasta
era_invalidate: Kommando nicht gefunden.
era_invalidate: kommandot finns inte
era_invalidate: komut yok
era_invalidate: nie znaleziono polecenia
era_invalidate: níor aimsíodh an t-ordú
era_invalidate: no se encontró la orden
era_invalidate: no s'ha trobat l'ordre
era_invalidate: opdracht niet gevonden
era_invalidate: parancs nem található
era_invalidate: perintah tidak ditemukan
era_invalidate: príkaz nenájdený
era_invalidate: příkaz nenalezen
era_invalidate: команда не найдена
era_invalidate: командата не е открита
era_invalidate: 命令找不到
era_invalidate: コマンドが見つかりません