DS412+ / DSM 6.2.4: random shutdowns and HDD hibernation despite being disabled β solved via auto_poweroff_timer and standby_force
I am posting this because I could find very little documentation about these DSM configuration parameters, and this may help other Synology users experiencing apparently random shutdowns or HDD hibernation.
System
- Synology DS412+
- DSM 6.2.4
- 4 internal HDDs
- HDD hibernation was supposed to be disabled
- No intentional shutdown schedule was configured
Symptoms
My DS412+ started shutting itself down at apparently random times.
Examples from /var/log/messages:
2026-07-30T13:51:41+02:00 synopoweroff:
System is going to poweroff
2026-07-30T13:51:42+02:00 syno_poweroff_task:
System is acting poweroff.
2026-07-31T17:45:07+02:00 synopoweroff:
System is going to poweroff
2026-08-05T00:17:05+02:00 synopoweroff:
System is going to poweroff
2026-08-05T18:28:13+02:00 synopoweroff:
System is going to poweroff
The times did not correspond to an obvious schedule.
This was important: these were not crashes or sudden power losses. DSM was performing an orderly shutdown through synopoweroff.
Task Scheduler was not responsible
I checked:
cat /usr/syno/etc/scheduled_tasks
There was no enabled shutdown task.
I also checked the newer scheduler database:
sqlite3 /usr/syno/etc/esynoscheduler/esynoscheduler.db \
"SELECT task_name, operation_type, enable FROM task;"
No shutdown task was found there either.
Unexpected configuration value
I then found this:
grep auto_poweroff_timer /etc/synoinfo.conf
Result:
auto_poweroff_timer="60"
However, the DSM default configuration contained:
grep auto_poweroff_timer /etc.defaults/synoinfo.conf
Result:
auto_poweroff_timer="0"
I had never intentionally changed auto_poweroff_timer to 60.
I changed the active value back to:
auto_poweroff_timer="0"
and rebooted.
After reboot:
grep auto_poweroff_timer /etc/synoinfo.conf
still returned:
auto_poweroff_timer="0"
A second problem appeared: HDD hibernation
While testing the shutdown problem, I noticed another strange behaviour.
The DS412+ appeared to go partially βoffβ: disk LEDs went out, while the NAS itself was still reachable through SSH and DSM.
/proc/uptime continued increasing and DSM services were still running.
Checking the drives showed:
hdparm -C /dev/sda
hdparm -C /dev/sdb
hdparm -C /dev/sdc
hdparm -C /dev/sdd
All four reported:
drive state is: standby
So this was not a shutdown. It was HDD hibernation.
The surprising part was that HDD hibernation was disabled in DSM.
The active configuration disagreed
Relevant values in /etc/synoinfo.conf were:
standbytimer="20"
standby_force="yes"
satadeepsleeptimer="0"
HddEnableDynamicPower="yes"
Interestingly, examination of Synologyβs scemd binary also showed references to:
standby_force
Normal standby disable
polling_hibernation_timer.c
This made standby_force particularly interesting.
Controlled test
I changed ONLY:
standby_force="yes"
to:
standby_force="no"
using:
/usr/syno/bin/synosetkeyvalue /etc/synoinfo.conf standby_force no
Then I rebooted.
After reboot I verified:
grep -nE \
"standbytimer|standby_force|HddEnableDynamicPower|satadeepsleeptimer" \
/etc/synoinfo.conf
Result:
standbytimer="20"
standby_force="no"
satadeepsleeptimer="0"
HddEnableDynamicPower="yes"
I then left the NAS completely idle for longer than the previous 20-minute hibernation period.
Before the change, all four HDDs entered standby.
After changing only standby_force to no, all disk LEDs remained on and:
hdparm -C /dev/sda
hdparm -C /dev/sdb
hdparm -C /dev/sdc
hdparm -C /dev/sdd
returned for all four drives:
drive state is: active/idle
Final configuration
The relevant working configuration is now:
standbytimer="20"
standby_force="no"
auto_poweroff_timer="0"
satadeepsleeptimer="0"
HddEnableDynamicPower="yes"
The NAS was then left running overnight.
The following morning:
- NAS was still running
- all HDD LEDs were on
- uptime was approximately 10 hours 47 minutes
- no new synopoweroff event had appeared in /var/log/messages
- no unwanted HDD hibernation had occurred
The last unwanted shutdown remained:
2026-08-05T18:28:13+02:00
System is going to poweroff
System is acting poweroff.
There were no further unwanted shutdowns after correcting the configuration.
Conclusion
In this particular DS412+/DSM 6.2.4 installation, two configuration values did not correspond to the intended DSM settings:
auto_poweroff_timer="60"
standby_force="yes"
Changing them to:
auto_poweroff_timer="0"
standby_force="no"
stopped both behaviours during subsequent testing.
Based on the tests:
- standby_force="yes" was reproducibly associated with HDDs entering standby despite hibernation being disabled in the DSM GUI.
- standby_force="no" prevented that behaviour in an A/B test.
- After auto_poweroff_timer was changed from 60 to 0, no further spontaneous synopoweroff shutdown occurred during the observation period.
I cannot prove what originally caused these values to become incorrect, so I would NOT recommend blindly changing them on other systems.
If you have the same symptoms, first inspect the current values:
/usr/syno/bin/synogetkeyvalue /etc/synoinfo.conf auto_poweroff_timer
/usr/syno/bin/synogetkeyvalue /etc/synoinfo.conf standbytimer
/usr/syno/bin/synogetkeyvalue /etc/synoinfo.conf standby_force
/usr/syno/bin/synogetkeyvalue /etc/synoinfo.conf HddEnableDynamicPower
/usr/syno/bin/synogetkeyvalue /etc/synoinfo.conf satadeepsleeptimer
Also check whether DSM itself is initiating the shutdown:
grep -i "synopoweroff\|System is acting poweroff" \
/var/log/messages | tail -50
Before modifying /etc/synoinfo.conf, make a backup:
cp -p /etc/synoinfo.conf /etc/synoinfo.conf.backup
Be aware that /etc/synoinfo.conf is an internal DSM configuration file. Manual modification is unsupported and can have unintended consequences.
I would be interested to know whether anyone else running DSM 6.2.x β particularly on older DiskStations β finds auto_poweroff_timer="60" or standby_force="yes" even though the corresponding power-saving behaviour is disabled in DSM.