ctdb_fetch_one: command not found

Have You tried accessing the binary with the full path?

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 Debian possible default full paths are:

/usr/lib/ctdb/tests/bin/ctdb_fetch_one - from package: ctdb-dbg

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