slapd: 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/slapd - from package: openldap-servers

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

On Debian possible default full paths are:

/usr/sbin/slapd - from package: slapd

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

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