slog: 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/slog - from package: sslogger

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

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