After doing a Ubuntu update, I found my droplet unbootable. Digital Ocean provides a useful utility ISO for restarting a droplet in recovery mode, but by itself I wasn’t able to see or fix the problem. Luckily I found a blog post with the correct set of remounts and chrooting to be able to rerun
apt and get everything running.
In order to get things running, you restart the droplet with the Recovery ISO as the startup drive, mount the main disk, choose 6 for interactive shell, then in the shell:
mount --bind /dev /mnt/dev mount --bind /proc /mnt/proc mount --bind /sys /mnt/sys mount --bind /run /mnt/run" chroot /mnt apt update apt upgrade
Restart the droplet and boot from main harddisk (you have to power cycle, a soft reboot doesn’t do the trick). After rebooting, I reran the updates just to make sure:
apt update apt upgrade apt autoremove
I found that not all my docker containers would come back up, and traced the failure to insufficient peak memory. This lead me to move my swap to a larger swapfile to allow for greater headroom.
fallocate -l 3G /swapfile3g ls -lh /swapfile ls -lh /swapfile3g chmod 600 /swapfile3g mkswap /swapfile3g swapon /swapfile3g swapon -s vi /etc/fstab swapoff /swapfile