grep-inode: 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/sbin/grep-inode - from package: lde

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

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