logfetch: 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 Debian possible default full paths are:

/usr/lib/xymon/client/bin/logfetch - from package: xymon-client

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

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