os_info: 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/os_info - from package: libstatgrab-examples

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

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