nsdb-nces: 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/nsdb-nces - from package: fedfs-utils-admin

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

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