ipa-upgradeconfig: 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/ipa-upgradeconfig - from package: ipa-server

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

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