我在 sa-east-1 区域有一个 Amazon EC2 Ubuntu t2.nano。它运行良好，直到 2017-06-14 维护。
今天，当我尝试通过 ssh 访问它时，我注意到这是不可能的。我收到 ssh 连接被拒绝的消息。然后我转到 aws 控制台并查看了两件事：
实例截图：
和系统日志（部分显示如下）：
[ 5.500346] systemd[1]: Starting Monitoring of LVM2 mirrors, snapshots etc. using dmeventd or progress polling...
Starting Monitoring of LVM2 mirrors... dmeventd or progress polling...
[ 5.513090] systemd[1]: Reached target Encrypted Volumes.
[[0;32m OK [0m] Reached target Encrypted Volumes.
[ 5.519554] systemd[1]: Listening on Journal Audit Socket.
[[0;32m OK [0m] Listening on Journal Audit Socket.
[ 5.527501] systemd[1]: Starting Journal Service...
Starting Journal Service...
[ 5.533351] systemd[1]: Set up automount Arbitrary Executable File Formats File System Automount Point.
[ 5.540655] Loading iSCSI transport class v2.0-870.
[[0;32m OK [0m] Set up automount Arbitrary Executab...ats File System Automount Point.
[ 5.551818] systemd[1]: Mounted Debug File System.
[[0;32m OK [0m] Mounted Debug File System.
[ 5.559413] systemd[1]: Mounted Huge Pages File System.
[[0;32m OK [0m] Mounted Huge Pages File System.
[ 5.567656] systemd[1]: Mounted POSIX Message Queue File System.
[[0;32m OK [0m] [ 5.573542] iscsi: registered transport (tcp)
Mounted POSIX Message Queue File System.
[ 5.578385] systemd[1]: Started Set console keymap.
[[0;32m OK [0m] Started Set console keymap.
[ 5.587286] systemd[1]: Started Create list of required static device nodes for the current kernel.
[[0;32m OK [0m] Started Create list of required sta...ce nodes for the current kernel.
[ 5.600884] systemd[1]: Started Uncomplicated firewall.
[[0;32m OK [0m] Started Uncomplicated firewall.
[ 5.607939] systemd[1]: Started Remount Root and Kernel File Systems.
[[0;32m OK [0m] Started Remount Root and Kernel File Systems.
[ 5.627380] systemd[1]: Started Nameserver information manager.
[[0;32m OK [0m[ 5.635695] iscsi: registered transport (iser)
] Started Nameserver information manager.
[ 5.642535] systemd[1]: Started Load Kernel Modules.
[[0;32m OK [0m] Started Load Kernel Modules.
[ 5.660181] systemd[1]: Started Journal Service.
[[0;32m OK [0m] Started Journal Service.
Starting Apply Kernel Variables...
Mounting FUSE Control File System...
[[0;32m OK [0m] Started LVM2 metadata daemon.
Starting Flush Journal to Persistent Storage...
Starting Initial cloud-init job (pre-networking)...
Starting udev Coldplug all Devices...
Starting Load/Save Random Seed...
Starting Create Static Device Nodes in /dev...
[[0;32m OK [0m] Mounted FUSE Control File System.
[[0;32m OK [0m] Started Apply Kernel Variables.
[[0;32m OK [0m] Started Load/Save Random Seed.
[[0;32m OK [0m] Started udev Coldplug all Devices.
[[0;32m OK [0m] Started Flush Journal to Persistent Storage.
[[0;32m OK [0m] Started Create Static Device Nodes in /dev.
Starting udev Kernel Device Manager...
[[0;32m OK [0m] Started udev Kernel Device Manager.
[[0;32m OK [0m] Started Dispatch Password Requests to Console Directory Watch.
[[0;32m OK [0m] Started Monitoring of LVM2 mirrors,...ng dmeventd or progress polling.
[[0;32m OK [0m] Reached target Local File Systems (Pre).
[[0;32m OK [0m] Found device /dev/ttyS0.
[[0;32m OK [0m] Found device /sys/subsystem/net/devices/eth0.
[[0;32m OK [0m] Listening on Load/Save RF Kill Switch Status /dev/rfkill Watch.
[ 8.686223] cloud-init[415]: Cloud-init v. 0.7.8 running 'init-local' at Thu, 15 Jun 2017 13:02:25 +0000. Up 8.20 seconds.
[[0;32m OK [0m] Started Initial cloud-init job (pre-networking).
[[0;32m OK [0m] Reached target Network (Pre).
[[0m[0;31m* [0m] A start job is running for dev-xvdf.device (8s / 1min 30s)
[K[[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (9s / 1min 30s)
[K[[0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (9s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (10s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (10s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m*[0m] A start job is running for dev-xvdf.device (11s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (11s / 1min 30s)
[K[ [0;31m*[0m] A start job is running for dev-xvdf.device (12s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (12s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m*[0m] A start job is running for dev-xvdf.device (13s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (13s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (14s / 1min 30s)
[K[[0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (14s / 1min 30s)
[K[[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (15s / 1min 30s)
[K[[0m[0;31m* [0m] A start job is running for dev-xvdf.device (15s / 1min 30s)
[K[[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (16s / 1min 30s)
[K[[0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (16s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (17s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (17s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m*[0m] A start job is running for dev-xvdf.device (18s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (18s / 1min 30s)
[K[ [0;31m*[0m] A start job is running for dev-xvdf.device (19s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (19s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m*[0m] A start job is running for dev-xvdf.device (20s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (20s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (21s / 1min 30s)
[K[[0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (21s / 1min 30s)
[K[[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (22s / 1min 30s)
[K[[0m[0;31m* [0m] A start job is running for dev-xvdf.device (22s / 1min 30s)
[K[[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (23s / 1min 30s)
[K[[0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (23s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (24s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (24s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m*[0m] A start job is running for dev-xvdf.device (25s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (25s / 1min 30s)
[K[ [0;31m*[0m] A start job is running for dev-xvdf.device (26s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (26s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m*[0m] A start job is running for dev-xvdf.device (27s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (27s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (28s / 1min 30s)
[K[[0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (28s / 1min 30s)
[K[[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (29s / 1min 30s)
[K[[0m[0;31m* [0m] A start job is running for dev-xvdf.device (29s / 1min 30s)
[K[[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (30s / 1min 30s)
[K[[0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (30s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (31s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (31s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m*[0m] A start job is running for dev-xvdf.device (32s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (32s / 1min 30s)
[K[ [0;31m*[0m] A start job is running for dev-xvdf.device (33s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (33s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m*[0m] A start job is running for dev-xvdf.device (34s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (34s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (35s / 1min 30s)
[K[[0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (35s / 1min 30s)
[K[[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (36s / 1min 30s)
[K[[0m[0;31m* [0m] A start job is running for dev-xvdf.device (36s / 1min 30s)
[K[[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (37s / 1min 30s)
[K[[0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (37s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (38s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (38s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m*[0m] A start job is running for dev-xvdf.device (39s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (39s / 1min 30s)
[K[ [0;31m*[0m] A start job is running for dev-xvdf.device (40s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (40s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m*[0m] A start job is running for dev-xvdf.device (41s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (41s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (42s / 1min 30s)
[K[[0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (42s / 1min 30s)
[K[[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (43s / 1min 30s)
[K[[0m[0;31m* [0m] A start job is running for dev-xvdf.device (43s / 1min 30s)
[K[[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (44s / 1min 30s)
[K[[0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (44s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (45s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (45s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m*[0m] A start job is running for dev-xvdf.device (46s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (46s / 1min 30s)
[K[ [0;31m*[0m] A start job is running for dev-xvdf.device (47s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (47s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m*[0m] A start job is running for dev-xvdf.device (48s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (48s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (49s / 1min 30s)
[K[[0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (49s / 1min 30s)
[K[[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (50s / 1min 30s)
[K[[0m[0;31m* [0m] A start job is running for dev-xvdf.device (50s / 1min 30s)
[K[[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (51s / 1min 30s)
[K[[0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (51s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (52s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (52s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m*[0m] A start job is running for dev-xvdf.device (53s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (53s / 1min 30s)
[K[ [0;31m*[0m] A start job is running for dev-xvdf.device (54s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (54s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m*[0m] A start job is running for dev-xvdf.device (55s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (55s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (56s / 1min 30s)
[K[[0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (56s / 1min 30s)
[K[[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (57s / 1min 30s)
[K[[0m[0;31m* [0m] A start job is running for dev-xvdf.device (57s / 1min 30s)
[K[[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (58s / 1min 30s)
[K[[0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (58s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (59s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (59s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m*[0m] A start job is running for dev-xvdf.device (1min / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (1min / 1min 30s)
[K[ [0;31m*[0m] A start job is running for dev-xvdf.device (1min 1s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (1min 1s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m*[0m] A start job is running for dev-xvdf.device (1min 2s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 2s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 3s / 1min 30s)
[K[[0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 3s / 1min 30s)
[K[[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 4s / 1min 30s)
[K[[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 4s / 1min 30s)
[K[[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 5s / 1min 30s)
[K[[0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 5s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 6s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 6s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m*[0m] A start job is running for dev-xvdf.device (1min 7s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (1min 7s / 1min 30s)
[K[ [0;31m*[0m] A start job is running for dev-xvdf.device (1min 8s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (1min 8s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m*[0m] A start job is running for dev-xvdf.device (1min 9s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 9s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 10s / 1min 30s)
[K[[0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 10s / 1min 30s)
[K[[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 11s / 1min 30s)
[K[[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 11s / 1min 30s)
[K[[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 12s / 1min 30s)
[K[[0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 12s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 13s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 13s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m*[0m] A start job is running for dev-xvdf.device (1min 14s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (1min 14s / 1min 30s)
[K[ [0;31m*[0m] A start job is running for dev-xvdf.device (1min 15s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (1min 15s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m*[0m] A start job is running for dev-xvdf.device (1min 16s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 16s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 17s / 1min 30s)
[K[[0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 17s / 1min 30s)
[K[[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 18s / 1min 30s)
[K[[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 18s / 1min 30s)
[K[[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 19s / 1min 30s)
[K[[0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 19s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 20s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 20s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m*[0m] A start job is running for dev-xvdf.device (1min 21s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (1min 21s / 1min 30s)
[K[ [0;31m*[0m] A start job is running for dev-xvdf.device (1min 22s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (1min 22s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m*[0m] A start job is running for dev-xvdf.device (1min 23s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 23s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 24s / 1min 30s)
[K[[0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 24s / 1min 30s)
[K[[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 25s / 1min 30s)
[K[[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 25s / 1min 30s)
[K[[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 26s / 1min 30s)
[K[[0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 26s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 27s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m* [0m] A start job is running for dev-xvdf.device (1min 27s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m[0;31m*[0m] A start job is running for dev-xvdf.device (1min 28s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (1min 28s / 1min 30s)
[K[ [0;31m*[0m] A start job is running for dev-xvdf.device (1min 29s / 1min 30s)
[K[ [0;31m*[0;1;31m*[0m] A start job is running for dev-xvdf.device (1min 29s / 1min 30s)
[K[[0;1;31m TIME [0m] Timed out waiting for device dev-xvdf.device.
[[0;1;33mDEPEND[0m] Dependency failed for /mnt/xvdf.
[[0;1;33mDEPEND[0m] Dependency failed for Local File Systems.
Starting Set console font and keymap...
[[0;32m OK [0m] Stopped getty on tty2-tty6 if dbus and logind are not available.
[[0;32m OK [0m] Stopped Getty on tty1.
[[0;32m OK [0m] Stopped Daily apt activities.
[[0;32m OK [0m] Closed Unix socket for apport crash forwarding.
[[0;32m OK [0m] Stopped Trigger resolvconf update for networkd DNS.
[[0;32m OK [0m] Stopped Daily Cleanup of Temporary Directories.
[[0;32m OK [0m] Closed UUID daemon activation socket.
[[0;32m OK [0m] Stopped Execute cloud user/final scripts.
[[0;32m OK [0m] Stopped Apply the settings specified in cloud-config.
[[0;32m OK [0m] Closed ACPID Listen Socket.
[[0;32m OK [0m] Stopped target Graphical Interface.
[[0;32m OK [0m] Stopped target Multi-User System.
[[0;32m OK [0m] Reached target Cloud-init target.
[[0;32m OK [0m] Stopped LSB: daemon to balance interrupts for SMP systems.
[[0;32m OK [0m] Stopped D-Bus System Message Bus.
[[0;32m OK [0m] Stopped Docker Application Container Engine.
[[0;32m OK [0m] Closed Docker Socket for the API.
[[0;32m OK [0m] Stopped LSB: MD monitoring daemon.
[[0;32m OK [0m] Stopped Terminate Plymouth Boot Screen.
[[0;32m OK [0m] Stopped LXD - container startup/shutdown.
[[0;32m OK [0m] Stopped System Logging Service.
[[0;32m OK [0m] Stopped OpenBSD Secure Shell server.
[[0;32m OK [0m] Stopped Pollinate to seed the pseudo random number generator.
[[0;32m OK [0m] Stopped LSB: Set the CPU Frequency Scaling governor to "ondemand".
[[0;32m OK [0m] Closed LXD - unix socket.
[[0;32m OK [0m] Stopped Auto import assertions from block devices.
[[0;32m OK [0m] Closed Syslog Socket.
[[0;32m OK [0m] Stopped Snappy daemon.
[[0;32m OK [0m] Stopped LSB: Set up cgroupfs mounts..
[[0;32m OK [0m] Stopped Service for virtual machines hosted on VMware.
[[0;32m OK [0m] Stopped Serial Getty on ttyS0.
[[0;32m OK [0m] Stopped Hold until boot process finishes up.
[[0;32m OK [0m] Stopped /etc/rc.local Compatibility.
[[0;32m OK [0m] Stopped Permit User Sessions.
Starting Set console scheme...
[[0;32m OK [0m] Reached target Login Prompts.
[[0;32m OK [0m] Stopped LSB: Record successful boot for GRUB.
[[0;32m OK [0m] Stopped noip2.service.
[[0;32m OK [0m] Stopped Deferred execution scheduler.
[[0;32m OK [0m] Stopped ACPI Events Check.
[[0;32m OK [0m] Stopped Login Service.
[[0;32m OK [0m] Stopped FUSE filesystem for LXC.
[[0;32m OK [0m] Stopped Accounts Service.
[[0;32m OK [0m] Stopped Timer to automatically refresh installed snaps.
[[0;32m OK [0m] Reached target Timers.
[[0;32m OK [0m] Stopped LSB: automatic crash report generation.
[[0;32m OK [0m] Closed D-Bus System Message Bus Socket.
[[0;32m OK [0m] Stopped Regular background program processing daemon.
[[0;32m OK [0m] Closed Socket activation for snappy daemon.
[[0;32m OK [0m] Stopped LSB: Apache2 web server.
[[0;32m OK [0m] Stopped target Basic System.
[[0;32m OK [0m] Reached target Paths.
[[0;32m OK [0m] Reached target Sockets.
[[0;32m OK [0m] Stopped target System Initialization.
Starting LSB: AppArmor initialization...
Starting Create Volatile Files and Directories...
[[0;32m OK [0m] Started Emergency Shell.
Starting Tell Plymouth To Write Out Runtime Data...
[[0;32m OK [0m] Reached target Emergency Mode.
[[0;32m OK [0m] Started Set console font and keymap.
[[0;32m OK [0m] Started Set console scheme.
[[0;32m OK [0m] Started Create Volatile Files and Directories.
Starting Network Time Synchronization...
Starting Update UTMP about System Boot/Shutdown...
[[0;32m OK [0m] Created slice system-getty.slice.
[[0;32m OK [0m] Started Tell Plymouth To Write Out Runtime Data.
[[0;32m OK [0m] Started Network Time Synchronization.
[[0;32m OK [0m] Reached target System Time Synchronized.
[[0;32m OK [0m] Started Update UTMP about System Boot/Shutdown.
Starting Update UTMP about System Runlevel Changes...
[[0;32m OK [0m] Started Update UTMP about System Runlevel Changes.
[[0;32m OK [0m] Started LSB: AppArmor initialization.
Starting Raise network interfaces...
[[0;32m OK [0m] Started ifup for eth0.
[[0;32m OK [0m] Started Raise network interfaces.
Starting Initial cloud-init job (metadata service crawler)...
[[0;32m OK [0m] Reached target Network.
[ 97.469232] cloud-init[923]: Cloud-init v. 0.7.8 running 'init' at Thu, 15 Jun 2017 13:03:54 +0000. Up 96.85 seconds.
[ 97.476693] cloud-init[923]: ci-info: +++++++++++++++++++++++++++++++++++++Net device info++++++++++++++++++++++++++++++++++++++
[ 97.484692] cloud-init[923]: ci-info: +--------+------+----------------------------+---------------+-------+-------------------+
[ 97.496661] cloud-init[923]: ci-info: | Device | Up | Address | Mask | Scope | Hw-Address |
[ 97.504676] cloud-init[923]: ci-info: +--------+------+----------------------------+---------------+-------+-------------------+
[ 97.512656] cloud-init[923]: ci-info: | eth0 | True | 172.31.28.229 | 255.255.240.0 | . | 02:92:48:51:32:d5 |
[ 97.520690] cloud-init[923]: ci-info: | eth0 | True | fe80::92:48ff:fe51:32d5/64 | . | link | 02:92:48:51:32:d5 |
[ 97.532598] cloud-init[923]: ci-info: | lo | True | 127.0.0.1 | 255.0.0.0 | . | . |[[0;32m OK [0m] Started Initial cloud-init job (metadata service crawler).
[[0;32m OK [0m
[ 97.540937] cloud-init[923]: ci-info: | lo | True | ::1/128 | . | host | . |] Reached target Cloud-config availability.
[[0;32m OK [0m] Reached target Network is Online.
[ 97.549254] cloud-init[923]: ci-info: +--------+------+----------------------------+---------------+-------+-------------------+ Starting iSCSI initiator daemon (iscsid)...
[ 97.557931] cloud-init[923]: ci-info: +++++++++++++++++++++++++++++Route IPv4 info+++++++++++++++++++++++++++++
[ 97.569483] cloud-init[923]: ci-info: +-------+-------------+-------------+---------------+-----------+-------+
[ 97.575302] cloud-init[923]: ci-info: | Route | Destination | Gateway | Genmask | Interface | Flags |
[ 97.579340] cloud-init[923]: ci-info: +-------+-------------+-------------+---------------+-----------+-------+
[ 97.583365] cloud-init[923]: ci-info: | 0 | 0.0.0.0 | 172.31.16.1 | 0.0.0.0 | eth0 | UG |
[ 97.587524] cloud-init[923]: ci-info: | 1 | 172.31.16.0 | 0.0.0.0 | 255.255.240.0 | eth0 | U |
[ 97.591777] cloud-init[923]: ci-info: +-------+-------------+-------------+---------------+-----------+-------+
[[0;32m OK [0m] Started iSCSI initiator daemon (iscsid).
Starting Login to default iSCSI targets...
[[0;32m OK [0m] Started Login to default iSCSI targets.
[[0;32m OK [0m] Reached target Remote File Systems (Pre).
[[0;32m OK [0m] Reached target Remote File Systems.
Welcome to emergency mode! After logging in, type "journalctl -xb" to view
system logs, "systemctl reboot" to reboot, "systemctl default" or ^D to
try again to boot into default mode.
Give root password for maintenance
(or press Control-D to continue):
似乎需要用户干预（不确定为什么）。
我尝试分离该卷并将其附加到另一个实例，但另一个实例也因类似问题而拒绝启动。所以我猜问题与该卷有关。
请问到底发生了什么事以及我是如何陷入这种情况的？
我该如何继续？
这只与 Ubuntu 有关吗？刚刚启动了 Amazon Linux 并将卷附加到它，至少在这里我可以安装它。