start-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/start-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/start-ds-admin - from package: 389-admin

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

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