diskseekd: 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/diskseekd - from package: fdutils

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