flashcache_create: 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:

/sbin/flashcache_create - from package: flashcache-utils

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

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