[smartmontools-support] can't enable Automatic Offline or Attribute Autosave even though supported

[Tom M. <tme...@gm...>]

When I used the directives '-o on' (offline data collection) and '-S on' 
(autosave attributes) (which seemed to be recommended) in my 
smartd.conf, I saw the following logged:

smartd: Device: /dev/sda, could not enable SMART Attribute Autosave.
smartd: Device: /dev/sda, enable SMART Automatic Offline Testing failed.

even though smartctl -a seems to suggest that these are supported:

# smartctl -a -d ata /dev/sda
smartctl version 5.36 ...
Device Model:     ST3320620AS
...
Device is:        Not in smartctl database
...
Offline data collection status:  (0x82) Offline data collection activity
                                         was completed without error.
                                   Auto Offline Data Collection: Enabled.
Offline data collection
capabilities:                    (0x5b) SMART execute Offline immediate.
                             Auto Offline data collection on/off support.
                                      Suspend Offline collection upon new
                                      command.
                                      Offline surface scan supported.
                                      Self-test supported.
                                      No Conveyance Self-test supported.
                                      Selective Self-test supported.
SMART capabilities:            (0x0003) Saves SMART data before entering
                                         power-saving mode.
                                         Supports SMART auto save timer.
...


The version of smartmontools I was using was one rev behind the
latest, so I downloaded and built the latest in a temporary directory
for testing. But even with the latest version I get:

# /tmp/sm/sbin/smartctl -o on -d ata /dev/sda
smartctl version 5.37 ...

=== START OF ENABLE/DISABLE COMMANDS SECTION ===
Error SMART Enable Automatic Offline failed: Input/output error
Smartctl: SMART Enable Automatic Offline Failed.


A bug?

  -Tom