A preliminary note of caution
I would advice against using email alerting for anything industry or mission critical, as email has issues with reliability among other things.
Prerequisites
ZFS is installed and configured, (install ZFS on Ubuntu Server).
Install msmtp and dependencies
msmtp is an SMTP client that is simple and easy to configure.
Fetch the latest version of the package list:
sudo apt update
Install msmtp along with msmtp-mta and mailutils:
sudo apt install -y msmtp msmtp-mta mailutils
Configure msmtp
Edit the /etc/msmtprc file (with root privileges), you can do this on Ubuntu using the sudoedit command:
sudoedit /etc/msmtprc
Note: You can easily change the sudoedit editor by setting the SUDO_EDITOR environment variable.
Edit the /etc/msmtprc file:
# Set default values for all following accounts.
defaults
auth on
tls on
tls_starttls on
tls_trust_file /etc/ssl/certs/ca-certificates.crt
# Outlook.
account outlook
host smtp-mail.outlook.com
port 587
from example_sender@outlook.com
user example_sender@outlook.com
password very_secret_password
# Gmail.
account gmail
host smtp.gmail.com
port 587
from example_sender@gmail.com
user example_sender@gmail.com
password much_different_password
Note: In this example, I have added templating for sending emails over TLS using either Gmail or Outlook. You can add other accounts by following the same format, (the account variable is required, but its value does not matter, it will not be used as an identifier).
Install ZED
ZED (ZFS Event Daemon) listens for ZFS events, and it can be configured to send email alerts after automated scrubs.
Install ZED:
sudo apt install zfs-zed
Configure ZED
Edit the ZED config file /etc/zfs/zed.d/zed.rc:
This configuration file is a little long, so I have included the relevant lines below. First up, the recipient email address of the alerts is set:
##
# Email address of the zpool administrator for receipt of notifications;
# multiple addresses can be specified if they are delimited by whitespace.
# Email will only be sent if ZED_EMAIL_ADDR is defined.
# Disabled by default; uncomment to enable.
#
ZED_EMAIL_ADDR="alert_me@example.com"
Then the mail command is set:
##
# Name or path of executable responsible for sending notifications via email;
# the mail program must be capable of reading a message body from stdin.
# Email will only be sent if ZED_EMAIL_ADDR is defined.
#
ZED_EMAIL_PROG="mail"
Then the command-line options for the mail command is set:
##
# Command-line options for ZED_EMAIL_PROG.
# The string @ADDRESS@ will be replaced with the recipient email address(es).
# The string @SUBJECT@ will be replaced with the notification subject;
# this should be protected with quotes to prevent word-splitting.
# Email will only be sent if ZED_EMAIL_ADDR is defined.
#
ZED_EMAIL_OPTS="-s '@SUBJECT@' @ADDRESS@ -r example_sender@outlook.com"
Note: The e-mail address after -r will determine the sender address of the alert email.
Finally (and optionally), the alerting verbosity is set, setting it to 1 will send alerts regardless of the pool health:
##
# Notification verbosity.
# If set to 0, suppress notification if the pool is healthy.
# If set to 1, send notification regardless of pool health.
#
ZED_NOTIFY_VERBOSE=1
Note: If you want to test the email alerts, set this variable to 1.
[Optional] Configure ZED scrubbing schedule
Interestingly, ZED on Ubuntu and Debian is pre-configured to perform a scrub on the second Sunday of each month (not a 🐛).
This feels like a pretty sane default, but if you want to change it, you can do so by editing the /etc/cron.d/zfsutils-linux file.
PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
# Scrub the second Sunday of every month.
24 0 8-14 * * root if [ $(date +\%w) -eq 0 ] && [ -x /usr/lib/zfs-linux/scrub ]; then /usr/lib/zfs-linux/scrub; fi
Note: This does a scrub on all ZFS storage pools. You can alternatively also delete the /etc/cron.d/zfsutils-linux file and configure a (root) cron job for each pool individually.
[Optional] Test ZFS scrub email alerts
If you want to test the email alerts, you can do so by creating a small ZFS test pool, scrubbing it, and then discarding it (source).
cd /tmp
dd if=/dev/zero of=zpool_test bs=1 count=0 seek=512M
sudo zpool create test /tmp/zpool_test
sudo zpool scrub test
sudo zpool export test
rm /tmp/zpool_test
Note: ZED_NOTIFY_VERBOSE=1 must be set in the ZED config file for this to work.