restart-ds-admin: 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/sbin/restart-ds-admin - from package: 389-admin

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

On Debian possible default full paths are:

/usr/sbin/restart-ds-admin - from package: 389-admin

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

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