dsktune: 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 CentOS possible default full paths are:

/usr/bin/dsktune - from package: 389-ds-base

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

On Debian possible default full paths are:

/usr/bin/dsktune - from package: 389-ds-base

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

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