texmfstart: 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/texmfstart - from package: texlive-context

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

On Debian possible default full paths are:

/usr/bin/texmfstart - from package: context

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

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