sdparm: 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 CentOS possible default full paths are:

/usr/bin/sdparm - from package: sdparm

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/sdparm - from package: sdparm

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