glance-cache-prefetcher: command not found

Have You tried accessing the binary with the full path?

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/glance-cache-prefetcher - from package: glance-api

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