syncache-drb: 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 Debian possible default full paths are:

/usr/bin/syncache-drb - from package: syncache

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

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