xarchiver: 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/xarchiver - from package: xarchiver

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

On Debian possible default full paths are:

/usr/bin/xarchiver - from package: xarchiver

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

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