liquibase: 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:

/usr/bin/liquibase - from package: liquibase

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

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