svscan: 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/bin/svscan - from package: daemontools

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