I was unable to connect to the server through winscp (after changing permissions of www directory of Apache server accidently), it shows Cannot initialize SFTP protocol. Is the host running a SFTP server? when executing this command in terminal sftp -P port-vv username@serverip ,I am getting the following response, what might be the problem?
debug2: we sent a password packet, wait for reply debug1: Authentication succeeded (password). Authenticated to ***** debug2: fd 4 setting O_NONBLOCK debug1: channel 0: new [client-session] debug2: channel 0: send open debug1: Requesting debug1: Entering interactive session. debug2: callback start debug2: client_session2_setup: id 0 debug2: fd 3 setting TCP_NODELAY debug1: Sending environment. debug1: Sending env LANG = en_US.UTF-8 debug2: channel 0: request env confirm 0 debug1: Sending subsystem: sftp debug2: channel 0: request subsystem confirm 1 debug2: callback done debug2: channel 0: open confirm rwindow 0 rmax 32768 debug2: channel 0: rcvd adjust 2097152 debug2: channel_input_status_confirm: type 99 id 0 debug2: subsystem request accepted on channel 0 debug1: client_input_channel_req: channel 0 rtype exit-status reply 0 debug1: client_input_channel_req: channel 0 rtype reply 0 debug2: channel 0: rcvd eow debug2: channel 0: close_read debug2: channel 0: input open -> closed debug2: channel 0: rcvd eof debug2: channel 0: output open -> drain debug2: channel 0: obuf empty debug2: channel 0: close_write debug2: channel 0: output drain -> closed debug2: channel 0: rcvd close debug2: channel 0: almost dead debug2: channel 0: gc: notify user debug2: channel 0: gc: user detached debug2: channel 0: send close debug2: channel 0: is dead debug2: channel 0: garbage collecting debug1: channel 0: free: client-session, nchannels 1 debug1: fd 0 clearing O_NONBLOCK Transferred: sent 1952, received 1960 bytes, in 0.3 seconds Bytes per second: sent 6473.8, received 6500.3 debug1: Exit status 141 1 Answer
OpenSSH runs a program called sftp-server when a client requests SFTP. In your case, the client requested SFTP, the server said "okay", then the SFTP channel closed:
debug1: Sending subsystem: sftp debug2: channel 0: request subsystem confirm 1 [snip] debug2: subsystem request accepted on channel 0 debug1: client_input_channel_req: channel 0 rtype exit-status reply 0 The simplest explanation is that the sftp-server program is missing from the server or can't be executed for some reason. You can't tell exactly what is wrong from the client. You'll have to troubleshoot this on the server.
On my system, the program is /usr/libexec/openssh/sftp-server, but it may be somewhere else for you.
