reposdump: 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/reposdump - from package: sblim-gather

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

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