FreeBSD install Error

[Georghy]

Hi folks,
I'm experiencing a problem when I try to install FreeBSD on a Virtual 
Server using KVM,
The first part of the installation was fine but after setting all the 
option (I use a custom installation of FreeBSD)
the installation encounter an error :
"Write failure on transfer! (wrote -1 bytes of 1425408 bytes)"
I tried to use "alt"+"2" but it doesn't show any clue for that error
Do you know how should I fix it ?

-- 
Cordialement, / Greetings,
Georghy FUSCO