If you are unfortunately working on a JUNOS chassis cluster that does not have the out-of-band management patched (fxp0) then you must use an alternate way to connect to specific nodes and copy files. You are able to copy files and login from to the non active node via the following methods.
To copy files or log in JUNOS gives you the following options:
Copy files from one node to another
Copy Method A, using CLI:
> file copy /var/tmp/abc.log node1:/var/log/
Copy Method B, using shell, follow the commands in order:
> start shell user root
% rcp -T /var/tmp/abc.log node1:/var/log/
Login from node0 to node1
The command mentioned does not work on 3k and 5k devices.
% rlogin -Jk -T node1 (This is shell command)