xfs_admin: 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_admin - from package: xfsprogs

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

On Debian possible default full paths are:

/usr/sbin/xfs_admin - from package: xfsprogs

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

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