xymond_channel: 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

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_channel - from package: xymon

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