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SSH 登录后关闭连接退出状态 254

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SSH 登录后关闭连接退出状态 254

首先我要声明的是，我已经阅读了这里与我相关的每一个问题，但他们似乎都以某种方式访问​​了他们服务器的文件。我没有，所以这是我的问题。

我在 centOS 6.5 上，成功登录后 ssh 立即关闭连接。我使用 mac 和 windows/putty 访问我的服务器，结果相同。有什么方法可以让我访问我的服务器，但无法访问其文件？

以下是成功登录后 ssh -vvv 的读数：

debug1: Authentication succeeded (password).
Authenticated to 4X.5X.XX.2 ([4X.5X.XX.2]:82).
debug1: channel 0: new [client-session]
debug3: ssh_session2_open: channel_new: 0
debug2: channel 0: send open
debug1: Requesting [email protected]
debug1: Entering interactive session.
debug2: callback start
debug2: fd 3 setting TCP_NODELAY
debug3: ssh_packet_set_tos: set IP_TOS 0x10
debug2: client_session2_setup: id 0
debug2: channel 0: request pty-req confirm 1
debug1: Sending environment.
debug3: Ignored env TERM_PROGRAM
debug3: Ignored env SHELL
debug3: Ignored env TERM
debug3: Ignored env TMPDIR
debug3: Ignored env Apple_PubSub_Socket_Render
debug3: Ignored env TERM_PROGRAM_VERSION
debug3: Ignored env TERM_SESSION_ID
debug3: Ignored env USER
debug3: Ignored env SSH_AUTH_SOCK
debug3: Ignored env __CF_USER_TEXT_ENCODING
debug3: Ignored env PATH
debug3: Ignored env PWD
debug1: Sending env LANG = en_US.UTF-8
debug2: channel 0: request env confirm 0
debug3: Ignored env XPC_FLAGS
debug3: Ignored env XPC_SERVICE_NAME
debug3: Ignored env SHLVL
debug3: Ignored env HOME
debug3: Ignored env LOGNAME
debug3: Ignored env _
debug2: channel 0: request shell confirm 1
debug2: callback done
debug2: channel 0: open confirm rwindow 0 rmax 32768
debug2: channel_input_status_confirm: type 99 id 0
debug2: PTY allocation request accepted on channel 0
debug2: channel 0: rcvd adjust 2097152
debug2: channel_input_status_confirm: type 99 id 0
debug2: shell request accepted on channel 0
Last login: Wed Oct  7 06:23:21 2015 from 1XX.XXX.X1.185
debug1: client_input_channel_req: channel 0 rtype exit-status reply 0
debug1: client_input_channel_req: channel 0 rtype [email protected] 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
debug3: channel 0: will not send data after 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
debug3: channel 0: status: The following connections are open:
  #0 client-session (t4 r0 i3/0 o3/0 fd -1/-1 cc -1)

Connection to 4X.5X.XX.2 closed.
Transferred: sent 3176, received 2640 bytes, in 0.3 seconds
Bytes per second: sent 10370.6, received 8620.4
debug1: Exit status 254

答案1

从记录来看，这肯定是分叉用户 shell 的问题。可能由以下原因造成：

  1. shell 初始化文件中的问题
  2. 内存不足的情况
  3. 进程外的情况

这是一个非常晚的答案，但在这种情况下，我会尝试直接执行一个命令，例如：ssh server ls -ltra可以绕过一些 shell 初始化，以另一个用户身份登录，使用一些不同的 shell 初始化文件，然后重新启动，这应该可以解决任何资源不足的情况。

答案2

我将内核参数文件 /etc/security/limits.conf 中的打开文件配置更改为无限制，从而失去了连接。

将 root 用户恢复为正常状态后，我恢复了连接。

Wrong Example:
## Example hard limit for max opened files
*        hard   nofile unlimited
root     hard   nofile  unlimited
## Example soft limit for max opened files
*        soft   nofile unlimited
root     soft   nofile unlimited

Correct Ex:
## Example hard limit for max opened files
*        hard   nofile 16000
root     hard   nofile 16000
## Example soft limit for max opened files
*        soft   nofile 16000
root     soft   nofile 16000

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