xsd: 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/xsd - from package: mono-web

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

On Debian possible default full paths are:

/usr/bin/xsd - from package: mono-devel

You may install the required package with command apt-get install {package}

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