verifytree: 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/verifytree - from package: yum-utils

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

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