nfsidmap: 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/nfsidmap - from package: nfs-utils

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

On Debian possible default full paths are:

/usr/sbin/nfsidmap - from package: nfs-common

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

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