smartmontools.service: Referenced but unset environment variable evaluates to an empty string: smartd_opts

[Sundar Nagarajan]

Output of lsb_release -rd
No LSB modules are available.
Description: Ubuntu 24.04.2 LTS
Release: 24.04

apt-cache policy smartmontools
smartmontools:
  Installed: 7.4-2build1
  Candidate: 7.4-2build1
  Version table:
 *** 7.4-2build1 500
        500 https://us.archive.ubuntu.com/ubuntu noble/main amd64 Packages
        100 /var/lib/dpkg/status

This warning (not error) appears in journalctl log:

smartmontools.service: Referenced but unset environment variable evaluates to an empty string: smartd_opts

Fix:
Add one line to /etc/default/smartmontools setting smartd_opts to an empty string

Existing file /etc/default/smartmontools:

# Defaults for smartmontools initscript (/etc/init.d/smartmontools)
# This is a POSIX shell fragment

# List of devices you want to explicitly enable S.M.A.R.T. for
# Not needed (and not recommended) if the device is monitored by smartd
#enable_smart="/dev/hda /dev/hdb"

# uncomment to pass additional options to smartd on startup
#smartd_opts="--interval=1800"

File with fix (additional line) added:
# Defaults for smartmontools initscript (/etc/init.d/smartmontools)
# This is a POSIX shell fragment

# List of devices you want to explicitly enable S.M.A.R.T. for
# Not needed (and not recommended) if the device is monitored by smartd
#enable_smart="/dev/hda /dev/hdb"

# uncomment to pass additional options to smartd on startup
#smartd_opts="--interval=1800"
smartd_opts=""

[Sundar Nagarajan (sundar-nagarajan)]

This affects smartmontools and not cron

[Christian Franke (christian-franke)]

Upstream fix for upcoming release 7.5: https://www.smartmontools.org/changeset/5651

[Bryce Harrington (bryce)]

Thanks for reporting this issue about the warning and a proposed fix, and thanks Christian for linking the upstream fix.

As plucky is past final freeze, this will need to wait to next cycle. And since the issue is a warning in a log, I doubt this will qualify for an SRU on its own (but could piggyback on another SRU for smartmontools if one appears). I'll add it to the server team's backlog but it is possible we'll just wait for when the next release of smartmontools is available to merge.

That said, if you'd like to try your hand at packaging the patch, we can provide advice on the process for getting it landed.