I run ZFS arrays on multiple machines, including the server our Phabricator is hosted on. I usually keep an eye on the disk arrays from time to time but if a drive fails you really want to know about it as soon as possible. I read quite some time ago about the ZFS Event Daemon, or "zed" but have been disappointed that it hasn't been included with the ZFS package even after various updates.

I recently noticed that one of the mirror arrays had become degraded after one of the drives had failed. After replacing the drive I decided to look into the ZED situation again. To my surprise it still hadn't been installed after recent updates so I decided to open my package manager GUI to see if there was a zed or zed alternative available. Of course there must have been some reason zed wasn't being installed right? Maybe it just was too experimental or something (despite not being able to find any information suggesting so)?

It only took a minute and saw that zed is a separate package to zfs. So... If you're running Ubuntu, are using ZFS but seem to have zed missing try:

sudo apt-get install zfs-zed

The daemon should be configured to run automatically on boot. To enable email notification be sure to edit /etc/zfs/zed.d/zed.rc to uncomment and set the ZED_EMAIL line. Make sure your system is set up to be able to send mail too.