vemerge: 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/sbin/vemerge - from package: util-vserver

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

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