将 Ubuntu 从 14.04 升级到 16.04 后，启动开始变得非常缓慢。似乎是交换分区的问题。下面我附上一些细节。
cat /var/log/boot.log
[FAILED] Failed to activate swap /dev/mapper/ubuntu--vg-swap_1.
See 'systemctl status "dev-mapper-ubunt...\x2dvg\\x2dswap_1.swap"' for details.
[DEPEND] Dependency failed for Swap.
...
[ TIME ] Timed out waiting for device dev-di...\x2db1dc\x2dae7fb1c172e6.device.
[DEPEND] Dependency failed for Cryptography Setup for cryptswap1.
[DEPEND] Dependency failed for dev-mapper-cryptswap1.device.
[DEPEND] Dependency failed for /dev/mapper/cryptswap1.
[DEPEND] Dependency failed for Encrypted Volumes.
猫 /etc/fstab
/dev/mapper/ubuntu--vg-root / ext4 errors=remount-ro 0 1
# /boot was on /dev/sda1 during installation
UUID=d57910fd-a1ae-4721-8da0-af0677f5a869 /boot ext2 defaults 0 …