ctdb_diagnostics: 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/bin/ctdb_diagnostics - from package: ctdb

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

On Debian possible default full paths are:

/usr/bin/ctdb_diagnostics - from package: ctdb

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

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