partclone.extfs: 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/sbin/partclone.extfs - from package: partclone

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