mkfontscale: 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/mkfontscale - from package: xorg-x11-font-utils

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

On Debian possible default full paths are:

/usr/bin/mkfontscale - from package: xfonts-utils

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

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