sss_groupdel: 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/sbin/sss_groupdel - from package: sssd-tools

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

On Debian possible default full paths are:

/usr/sbin/sss_groupdel - from package: sssd-tools

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