我正在使用 putty 连接到 Ubuntu 15.10 的虚拟盒安装：
Welcome to Ubuntu 15.10 (GNU/Linux 4.2.0-22-generic x86_64)
如果这样做，只需cd folde [tab]打开一个窗口
"Connection closed by remote host"
我完全不知道哪里出了问题、如何解决这个问题以及这个问题是从哪里突然出现的。
编辑：新信息：这似乎不会以 root 身份发生。
到目前为止我已经尝试过：
- 升级 ubuntu
- 测试了 mobaxterm 和 simple putty
- 将 Putty 安装在任何其他机器上均可正常工作
- 这不是由于内存不足：MemTotal：9996524 kB，MemFree：9422540 kB，MemAvailable：9830548 kB
- 使用 exec bash 启动另一个 bash 将使问题出现的频率降低。
beginner@avalon:~$ sudo tail -100f /var/log/syslog
[sudo] password for beginner:
Dec 21 10:50:44 avalon whoopsie[574]: [10:50:44] online
Dec 21 10:50:48 avalon NetworkManager[623]: <info> WiFi hardware radio set enabled
Dec 21 10:50:48 avalon NetworkManager[623]: <info> WWAN hardware radio set enabled
Dec 21 10:50:52 avalon ntpdate[865]: no server suitable for synchronization found
Dec 21 10:51:02 avalon ntpdate[1035]: no server suitable for synchronization found
Dec 21 10:52:08 avalon systemd[1]: dev-disk-by\x2duuid-66341dbb\x2d4e46\x2d4bcd\x2d89ad\x2d9b40aa873fe6.device: Job dev-disk-by\x2duuid-66341dbb\x2d4e46\x2d4bcd\x2d89ad\x2d9b40aa873fe6.device/start timed out.
Dec 21 10:52:08 avalon systemd[1]: Timed out waiting for device dev-disk-by\x2duuid-66341dbb\x2d4e46\x2d4bcd\x2d89ad\x2d9b40aa873fe6.device.
Dec 21 10:52:08 avalon systemd[1]: Dependency failed for /dev/disk/by-uuid/66341dbb-4e46-4bcd-89ad-9b40aa873fe6.
Dec 21 10:52:08 avalon systemd[1]: dev-disk-by\x2duuid-66341dbb\x2d4e46\x2d4bcd\x2d89ad\x2d9b40aa873fe6.swap: Job dev-disk-by\x2duuid-66341dbb\x2d4e46\x2d4bcd\x2d89ad\x2d9b40aa873fe6.swap/start failed with result 'dependency'.
Dec 21 10:52:08 avalon systemd[1]: Startup finished in 9.395s (kernel) + 3min 519ms (userspace) = 3min 9.914s.
Dec 21 10:52:08 avalon systemd[1]: dev-disk-by\x2duuid-66341dbb\x2d4e46\x2d4bcd\x2d89ad\x2d9b40aa873fe6.device: Job dev-disk-by\x2duuid-66341dbb\x2d4e46\x2d4bcd\x2d89ad\x2d9b40aa873fe6.device/start failed with result 'timeout'.
Dec 21 11:04:03 avalon systemd[1]: Starting Cleanup of Temporary Directories...
Dec 21 11:04:03 avalon systemd-tmpfiles[1074]: [/usr/lib/tmpfiles.d/var.conf:14] Duplicate line for path "/var/log", ignoring.
Dec 21 11:04:03 avalon systemd[1]: Started Cleanup of Temporary Directories.
Dec 21 11:08:14 avalon systemd[1]: Created slice user-1001.slice.
Dec 21 11:08:14 avalon systemd[1]: Starting User Manager for UID 1001...
Dec 21 11:08:14 avalon systemd[1]: Started Session 1 of user beginner.
Dec 21 11:08:14 avalon systemd[1084]: Reached target Paths.
Dec 21 11:08:14 avalon systemd[1084]: Reached target Timers.
Dec 21 11:08:14 avalon systemd[1084]: Reached target Sockets.
Dec 21 11:08:14 avalon systemd[1084]: Reached target Basic System.
Dec 21 11:08:14 avalon systemd[1084]: Reached target Default.
Dec 21 11:08:14 avalon systemd[1084]: Startup finished in 26ms.
Dec 21 11:08:14 avalon systemd[1]: Started User Manager for UID 1001.
Dec 21 11:08:14 avalon systemd[1]: Started Session 2 of user beginner.
Dec 21 11:08:18 avalon systemd[1]: Stopping User Manager for UID 1001...
Dec 21 11:08:18 avalon systemd[1084]: Reached target Shutdown.
Dec 21 11:08:18 avalon systemd[1084]: Starting Exit the Session...
Dec 21 11:08:18 avalon systemd[1084]: Stopped target Default.
Dec 21 11:08:18 avalon systemd[1084]: Stopped target Basic System.
Dec 21 11:08:18 avalon systemd[1084]: Stopped target Sockets.
Dec 21 11:08:18 avalon systemd[1084]: Stopped target Timers.
Dec 21 11:08:18 avalon systemd[1084]: Stopped target Paths.
Dec 21 11:08:18 avalon systemd[1084]: Received SIGRTMIN+24 from PID 1215 (kill).
Dec 21 11:08:18 avalon systemd[1]: Stopped User Manager for UID 1001.
Dec 21 11:08:18 avalon systemd[1]: Removed slice user-1001.slice.
Dec 21 11:08:19 avalon systemd[1]: Created slice user-1001.slice.
Dec 21 11:08:19 avalon systemd[1]: Starting User Manager for UID 1001...
Dec 21 11:08:19 avalon systemd[1]: Started Session 3 of user beginner.
Dec 21 11:08:19 avalon systemd[1223]: Reached target Sockets.
Dec 21 11:08:19 avalon systemd[1223]: Reached target Timers.
Dec 21 11:08:19 avalon systemd[1223]: Reached target Paths.
Dec 21 11:08:19 avalon systemd[1223]: Reached target Basic System.
Dec 21 11:08:19 avalon systemd[1223]: Reached target Default.
Dec 21 11:08:19 avalon systemd[1223]: Startup finished in 14ms.
Dec 21 11:08:19 avalon systemd[1]: Started User Manager for UID 1001.
Dec 21 11:08:20 avalon systemd[1]: Started Session 4 of user beginner.
Dec 21 11:08:39 avalon systemd[1]: Stopping User Manager for UID 1001...
Dec 21 11:08:39 avalon systemd[1223]: Reached target Shutdown.
Dec 21 11:08:39 avalon systemd[1223]: Starting Exit the Session...
Dec 21 11:08:39 avalon systemd[1223]: Stopped target Default.
Dec 21 11:08:39 avalon systemd[1223]: Stopped target Basic System.
Dec 21 11:08:39 avalon systemd[1223]: Stopped target Sockets.
Dec 21 11:08:39 avalon systemd[1223]: Stopped target Timers.
Dec 21 11:08:39 avalon systemd[1223]: Stopped target Paths.
Dec 21 11:08:39 avalon systemd[1223]: Received SIGRTMIN+24 from PID 1308 (kill).
Dec 21 11:08:39 avalon systemd[1]: Stopped User Manager for UID 1001.
Dec 21 11:08:39 avalon systemd[1]: Removed slice user-1001.slice.
Dec 21 11:08:46 avalon systemd[1]: Created slice user-1001.slice.
Dec 21 11:08:46 avalon systemd[1]: Starting User Manager for UID 1001...
Dec 21 11:08:46 avalon systemd[1]: Started Session 5 of user beginner.
Dec 21 11:08:46 avalon systemd[1318]: Reached target Paths.
Dec 21 11:08:46 avalon systemd[1318]: Reached target Sockets.
Dec 21 11:08:46 avalon systemd[1318]: Reached target Timers.
Dec 21 11:08:46 avalon systemd[1318]: Reached target Basic System.
Dec 21 11:08:46 avalon systemd[1318]: Reached target Default.
Dec 21 11:08:46 avalon systemd[1318]: Startup finished in 17ms.
Dec 21 11:08:46 avalon systemd[1]: Started User Manager for UID 1001.
Dec 21 11:08:46 avalon systemd[1]: Started Session 6 of user beginner.
Dec 21 11:09:44 avalon systemd[1]: dev-disk-by\x2duuid-66341dbb\x2d4e46\x2d4bcd\x2d89ad\x2d9b40aa873fe6.device: Job dev-disk-by\x2duuid-66341dbb\x2d4e46\x2d4bcd\x2d89ad\x2d9b40aa873fe6.device/start timed out.
Dec 21 11:09:44 avalon systemd[1]: Timed out waiting for device dev-disk-by\x2duuid-66341dbb\x2d4e46\x2d4bcd\x2d89ad\x2d9b40aa873fe6.device.
Dec 21 11:09:44 avalon systemd[1]: Dependency failed for /dev/disk/by-uuid/66341dbb-4e46-4bcd-89ad-9b40aa873fe6.
Dec 21 11:09:44 avalon systemd[1]: dev-disk-by\x2duuid-66341dbb\x2d4e46\x2d4bcd\x2d89ad\x2d9b40aa873fe6.swap: Job dev-disk-by\x2duuid-66341dbb\x2d4e46\x2d4bcd\x2d89ad\x2d9b40aa873fe6.swap/start failed with result 'dependency'.
Dec 21 11:09:44 avalon systemd[1]: dev-disk-by\x2duuid-66341dbb\x2d4e46\x2d4bcd\x2d89ad\x2d9b40aa873fe6.device: Job dev-disk-by\x2duuid-66341dbb\x2d4e46\x2d4bcd\x2d89ad\x2d9b40aa873fe6.device/start failed with result 'timeout'.
Dec 21 11:16:00 avalon systemd[1]: Started Session 7 of user beginner.
Dec 21 11:16:00 avalon systemd[1]: Started Session 8 of user beginner.
Dec 21 11:16:21 avalon systemd[1]: Started Session 9 of user beginner.
Dec 21 11:16:21 avalon systemd[1]: Started Session 10 of user beginner.
Dec 21 11:17:01 avalon CRON[2542]: (root) CMD ( cd / && run-parts --report /etc/cron.hourly)
Dec 21 11:17:54 avalon systemd[1]: Started Session 12 of user beginner.
Dec 21 11:17:54 avalon systemd[1]: Started Session 13 of user beginner.
Dec 21 11:19:42 avalon systemd[1]: Started Session 14 of user beginner.
Dec 21 11:23:41 avalon systemd[1]: Started Session 15 of user beginner.
Dec 21 11:24:27 avalon systemd[1]: Started Session 16 of user beginner.
Dec 21 11:34:47 avalon systemd[1]: Started Session 17 of user beginner.
Dec 21 11:34:47 avalon systemd[1]: Started Session 18 of user beginner.
Dec 21 11:35:49 avalon systemd[1]: Started Session 19 of user beginner.
Dec 21 11:35:49 avalon systemd[1]: Started Session 20 of user beginner.
Dec 21 11:35:53 avalon systemd[1]: Started Session 21 of user beginner.
Dec 21 11:35:53 avalon systemd[1]: Started Session 22 of user beginner.
Dec 21 11:36:23 avalon systemd[1]: Started Session 23 of user beginner.
Dec 21 11:36:23 avalon systemd[1]: Started Session 24 of user beginner.
Dec 21 11:40:10 avalon systemd[1]: Started Session 25 of user beginner.
Dec 21 11:40:10 avalon systemd[1]: Started Session 26 of user beginner.
Dec 21 11:41:17 avalon systemd[1]: Started Session 27 of user beginner.
Dec 21 11:41:17 avalon systemd[1]: Started Session 28 of user beginner.
Dec 21 11:52:24 avalon systemd[1]: Started Session 29 of user beginner.
Dec 21 11:52:24 avalon systemd[1]: Started Session 30 of user beginner.
Dec 21 11:52:29 avalon systemd[1]: Started Session 31 of user beginner.
Dec 21 11:52:29 avalon systemd[1]: Started Session 32 of user beginner.
$ sudo crontab -e
[sudo] password for beginner:
no crontab for root - using an empty one
检查文件 /etc/crontab：
$ sudo less /etc/contab
# /etc/crontab: system-wide crontab
# Unlike any other crontab you don't have to run the `crontab'
# command to install the new version when you edit this file
# and files in /etc/cron.d. These files also have username fields,
# that none of the other crontabs do.
SHELL=/bin/sh
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
# m h dom mon dow user command
17 * * * * root cd / && run-parts --report /etc/cron.hourly
25 6 * * * root test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.daily )
47 6 * * 7 root test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.weekly )
52 6 1 * * root test -x /usr/sbin/anacron || ( cd / && run-parts --report /etc/cron.monthly )
#
cron.daily 和 cron.hourly 中的文件
raphael@frankfurt:~$ ls /etc/cron*
/etc/crontab
/etc/cron.d:
anacron
/etc/cron.daily:
0anacron bsdmainutils logrotate passwd upstart
apport cracklib-runtime man-db popularity-contest
apt dpkg mlocate update-notifier-common
/etc/cron.hourly:
磁盘空间似乎很好：
Filesystem Size Used Avail Use% Mounted on
udev 4.8G 0 4.8G 0% /dev
tmpfs 977M 9.0M 968M 1% /run
/dev/sda1 40G 11G 28G 28% /
tmpfs 4.8G 4.0K 4.8G 1% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 4.8G 0 4.8G 0% /sys/fs/cgroup
cgmfs 100K 0 100K 0% /run/cgmanager/fs
tmpfs 977M 4.0K 977M 1% /run/user/1001
答案1
问题如下：
我正在寻找一些脚本来设置我的环境。其中一个脚本包含
set -e
任何导致错误的因素都会停止 bash 的执行。
经验教训：永远不要set -e在.bashrc中。
编辑：正如 NicoMinsk 指出的那样，可以在 bashrc 的末尾设置 -e 而不会出现任何问题。