I am trying to cpoy the file form one machine to an other.

[root@skia /]# scp iso.iso root@akroneiro:/root
root@akroneiro's password:

[root@skia /]#

No error message appears.... !!! But the file can't be found anywhere!!!

I have tried the same command at collegue but it had worked fine

Can you connect to the host akroneiro as root just using ssh itself?

Also try using scp -vvv to get verbose debugging messages.

You may also wan't to check that you didn't just create a file on / called "root".

After the authentication is completed i receive this messages propable from the copy ...
debug1: channel 0: read<=0 rfd 4 len 0
debug1: channel 0: read failed
debug1: channel 0: close_read
debug1: channel 0: input open -> drain
debug1: channel 0: ibuf empty
debug1: channel 0: send eof
debug1: channel 0: input drain -> closed
[root@skia /]# debug1: channel 0: write failed
debug1: channel 0: close_write
debug1: channel 0: output open -> closed
debug1: channel 0: rcvd eof
debug1: client_input_channel_req: channel 0 rtype exit-status reply 0
debug1: channel 0: rcvd close
debug1: channel 0: almost dead
debug1: channel 0: gc: notify user
debug1: channel 0: gc: user detached
debug1: channel 0: send close
debug1: channel 0: is dead
debug1: channel 0: garbage collecting
debug1: channel_free: channel 0: client-session, nchannels 1
debug1: fd 0 clearing O_NONBLOCK
debug1: fd 1 clearing O_NONBLOCK
debug1: Transferred: stdin 0, stdout 0, stderr 0 bytes in 0.2 seconds
debug1: Bytes per second: stdin 0.0, stdout 0.0, stderr 0.0
debug1: Exit status 0

Considering an ISO is usually quite large do you have enough space on your / partition?

Yep the Iso is about the 70 mb and the other pc has about 1gb free space