xfs_ncheck: 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/xfs_ncheck - from package: xfsprogs

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

On Debian possible default full paths are:

/usr/sbin/xfs_ncheck - from package: xfsprogs

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

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