xymond_history: 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/xymon/server/bin/xymond_history - from package: xymon

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