g2root: 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/g2root - from package: root-hbook

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

On Debian possible default full paths are:

/usr/bin/g2root - from package: root-plugin-hist-hbook

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

Error in other languages:
g2root: bevel nie gevind nie
g2root: comandă negăsită
g2root: comando não encontrado
g2root: commande introuvable
g2root: command not found
g2root: käsku ei ole
g2root: không tìm thấy lệnh
g2root: komanda nerasta
g2root: Kommando nicht gefunden.
g2root: kommandot finns inte
g2root: komut yok
g2root: nie znaleziono polecenia
g2root: níor aimsíodh an t-ordú
g2root: no se encontró la orden
g2root: no s'ha trobat l'ordre
g2root: opdracht niet gevonden
g2root: parancs nem található
g2root: perintah tidak ditemukan
g2root: príkaz nenájdený
g2root: příkaz nenalezen
g2root: команда не найдена
g2root: командата не е открита
g2root: 命令找不到
g2root: コマンドが見つかりません