我遇到了无法使用 SSH 连接和访问我的 EC2 的问题，并且显示连接超时。创建 EC2 后，我可以连接和访问。3 分钟后，我无法连接和访问它。请告诉我如何解决这个问题？
[ 7.540187] cloud-init[1047]: Cloud-init v. 17.1 running 'init' at Wed, 20 Dec 2017 08:53:52 +0000. Up 7.27 seconds.
[ 7.548824] cloud-init[1047]: ci-info: ++++++++++++++++++++++++++++++++++++++Net device info++++++++++++++++++++++++++++++++++++++
[ 7.560826] cloud-init[1047]: ci-info: +--------+------+-----------------------------+---------------+-------+-------------------+
[ 7.572244] cloud-init[1047]: ci-info: | Device | Up | Address | Mask | Scope | Hw-Address |
[ 7.580877] cloud-init[1047]: ci-info: +--------+------+-----------------------------+---------------+-------+-------------------+
[ 7.592982] cloud-init[1047]: ci-info: | eth0 | True | 172.31.20.209 | 255.255.240.0 | . | 06:0c:2a:5e:5b:be |
[ 7.604832] cloud-init[1047]: ci-info: | eth0 | True | fe80::40c:2aff:fe5e:5bbe/64 | . | link | 06:0c:2a:5e:5b:be |
[ 7.616448] cloud-init[1047]: ci-info: | lo | True | 127.0.0.1 | 255.0.0.0 | . | . |[[0;32m OK [0m] Started Initial cloud-init job (metadata service crawler).
[ 7.625744] cloud-init[1047]: ci-info: | lo | True | ::1/128 | . | host | . |
[[0;32m OK [0m] Reached target Cloud-config availability.
[[0;32m OK [0m
[ 7.636537] cloud-init[1047]: ci-info: +--------+------+-----------------------------+---------------+-------+-------------------+] Reached target Network is Online.
Starting iSCSI initiator daemon (iscsid)...
[[0;32m OK [0m] Reached target System Initialization.
[ 7.648807] cloud-init[1047]: ci-info: +++++++++++++++++++++++++++++Route IPv4 info+++++++++++++++++++++++++++++
[[0;32m OK [0m] Listening on UUID daemon activation socket.
[ 7.657063] cloud-init
[[0;32m OK [0m] Listening on ACPID Listen Socket.
[1047]: ci-info: +-------+-------------+-------------+---------------+-----------+-------+
[[0;32m OK [0m] Started Timer to automatically refresh installed snaps.
[ 7.672702] cloud-init[1047]: [[0;32m OK [0m] Started Daily Cleanup of Temporary Directories.
Starting Socket activation for snappy daemon.ci-info: | Route | Destination | Gateway | Genmask | Interface | Flags |
[ 7.684164] cloud-init[1047]: ci-info: +-------+-------------+-------------+---------------+-----------+-------+
[[0;32m OK [0m] Started Daily apt download activities.
[[0;32m OK [0m] Started Daily apt upgrade and clean activities.
[[0;32m OK [0m] Reached target Timers.[ 7.696431] cloud-init[1047]: ci-info: | 0 | 0.0.0.0 | 172.31.16.1 | 0.0.0.0 | eth0 | UG |
[ 7.700455] cloud-init[1047]: ci-info: | 1 | 172.31.16.0 | 0.0.0.0 | 255.255.240.0 | eth0 | U |
Starting LXD - unix socket.
[[0;32m OK [0m] Listening on D-Bus System Message Bus Socket.
[ 7.705061] cloud-init[1047]: ci-info: +-------+-------------+-------------+---------------+-----------+-------+
[[0;32m OK [0m] Started ACPI Events Check.
[[0;32m OK [0m] Reached target Paths.
[[0;32m OK [0m] Listening on Socket activation for snappy daemon.
[[0;32m OK [0m] Listening on LXD - unix socket.
[[0;32m OK [0m] Started iSCSI initiator daemon (iscsid).
Starting Login to default iSCSI targets...
[[0;32m OK [0m] Reached target Sockets.
[[0;32m OK [0m] Reached target Basic System.
Starting LSB: MD monitoring daemon...
Starting LXD - container startup/shutdown...
[[0;32m OK [0m] Started ACPI event daemon.
Starting Snappy daemon...
[[0;32m OK [0m] Started Unattended Upgrades Shutdown.
Starting /etc/rc.local Compatibility...
Starting LSB: Record successful boot for GRUB...
[[0;32m OK [0m] Started Regular background program processing daemon.
Starting A high performance web server and a reverse proxy server...
[[0;32m OK [0m] Started D-Bus System Message Bus.
Starting Apply the settings specified in cloud-config...
[[0;32m OK [0m] Started FUSE filesystem for LXC.
[[0;32m OK [0m] Started Deferred execution scheduler.
Starting System Logging Service...
Starting Login Service...
Starting Accounts Service...
Starting OpenBSD Secure Shell server...
[[0;32m OK [0m] Started LXD - container startup/shutdown.
[[0;32m OK [0m] Started /etc/rc.local Compatibility.
[[0;32m OK [0m] Started Login to default iSCSI targets.
[[0;32m OK [0m] Started LSB: MD monitoring daemon.
[[0;32m OK [0m] Started OpenBSD Secure Shell server.
[[0;32m OK [0m] Started Snappy daemon.
[[0;32m OK [0m] Started LSB: Record successful boot for GRUB.
[[0;32m OK [0m] Started A high performance web server and a reverse proxy server.
[[0;32m OK [0m] Started Login Service.
Starting Authenticate and Authorize Users to Run Privileged Tasks...
[[0;32m OK [0m] Reached target Remote File Systems (Pre).
[[0;32m OK [0m] Reached target Remote File Systems.
Starting LSB: Set the CPU Frequency Scaling governor to "ondemand"...
Starting LSB: automatic crash report generation...
Starting Permit User Sessions...
Starting LSB: daemon to balance interrupts for SMP systems...
[[0;32m OK [0m] Started Permit User Sessions.
[[0;32m OK [0m] Started Authenticate and Authorize Users to Run Privileged Tasks.
[[0;32m OK [0m] Started Accounts Service.
Starting Hold until boot process finishes up...
Starting Terminate Plymouth Boot Screen...
[[0;32m OK [0m] Started LSB: Set the CPU Frequency Scaling governor to "ondemand".
[[0;32m OK [0m] Started LSB: automatic crash report generation.
[[0;32m OK [0m] Started Hold until boot process finishes up.
[[0;32m OK [0m] Started Terminate Plymouth Boot Screen.
[[0;32m OK [0m] Started Getty on tty1.
[[0;32m OK [0m] Started Serial Getty on ttyS0.
[[0;32m OK [0m] Reached target Login Prompts.
Starting Set console scheme...
[[0;32m OK [0m] Started LSB: daemon to balance interrupts for SMP systems.
[[0;32m OK [0m] Started Set console scheme.
[ 8.617050] cloud-init[1147]: Cloud-init v. 17.1 running 'modules:config' at Wed, 20 Dec 2017 08:53:53 +0000. Up 8.52 seconds.
[[0;32m OK [0m] Started Apply the settings specified in cloud-config.
答案1
从我看到和经历的情况来看，私钥未被接受或访问写入错误。尝试使用以下指南设置连接。
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/AccessingInstancesLinux.html
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/putty.html
答案2
最好的办法是等待 20 分钟，然后再试一次，并仔细检查控制台输出。您很可能发现了一个 cloud-init 错误，该错误在初始启动后应用了配置更改或软件包升级序列，并导致一段时间的中断。有时，当发生这种情况时，已发布的 AMI 配置会尝试在启动时更新操作系统或“寻求”远程指令以完成其初始配置。如果是这种情况，您需要等待这些过程完成，直到完成并且 SSH 再次可用。
要明确测试这种情况的方法：启动一个新图像，尽可能登录，保持开放并查看该会话是否被服务器终止。三分钟后尝试单独登录；如果第一个会话没有被终止，请使用该会话来排除故障。如果曾是杀死，尝试等待大约 30 分钟（假设它是一个 t2.micro 实例）然后重试。
还要确认您的网络 ACL 确实正确地传递了流量，以及您的实例正在使用的安全组。您的实例几乎肯定会在初始化时尝试连接互联网，这意味着任何无法访问 DNS（传出 UDP 流量）的情况都会延迟初始化过程，并使启动后配置缓慢，因为每个程序步骤都要等待超时才能继续下一步。
如果 30 分钟后你的实例仍然不可用，那么停止然后重新启动映像可能会有所帮助（cloud-init我相信不会在重启时运行，因为它已经初始化）。
否则，你需要
- 启动你知道正在运行的图像位于同一可用区，
- 确认你可以达到
- 然后停止它，
- 关闭或停止不工作的那个
- 并分离其体积；
- 然后，您可以将非工作卷中的卷作为额外磁盘附加到工作实例上，
- 重新启动工作实例，
- 登录工作实例，
- 然后从故障实例安装磁盘并手动检查其日志和配置。