我的 Ubuntu 12.04 服务器有一个奇怪的问题。
通过 ssh 正确登录后，连接立即关闭。
这是我登录后在控制台上得到的输出ssh -vvv：
Welcome to Ubuntu 12.04.1 LTS (GNU/Linux 3.2.0-32-generic x86_64)
* Documentation: https://help.ubuntu.com/
System information as of Mon Mar 4 10:29:54 CET 2013
System load: 0.18 Processes: 120
Usage of /: 2.9% of 77.23GB Users logged in: 0
Memory usage: 54% IP address for eth0: x.x.x.x
Swap usage: 9%
Graph this data and manage this system at https://landscape.canonical.com/
174 packages can be updated.
61 updates are security updates.
Last login: Mon Mar 4 10:29:28 2013 from y.y.y.y
debug3: channel 0: will not send data after close
debug2: channel 0: obuf empty
debug2: channel 0: close_write
debug2: channel 0: output drain -> closed
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
debug3: channel 0: status: The following connections are open:
#0 client-session (t4 r0 i3/0 o3/0 fd -1/-1 cfd -1)
debug3: channel 0: close_fds r -1 w -1 e 6 c -1
Connection to x.x.x.x closed.
debug1: Transferred: stdin 0, stdout 0, stderr 39 bytes in 0.7 seconds
debug1: Bytes per second: stdin 0.0, stdout 0.0, stderr 58.4
debug1: Exit status 1`
目前不允许 root 直接通过 ssh 连接，所以我只有一个用户可以登录。此外，没有 X-Server，只有控制台。
有任何想法吗？
提前致谢！