svnsync: 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/svnsync - from package: subversion

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

On Debian possible default full paths are:

/usr/bin/svnsync - from package: subversion

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

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