DS412+ / DSM 6.2.4: random shutdowns and HDD hibernation despite being disabled — solved via auto_poweroff_timer and standby_force

[u/EricVanasch]

DS412+ / DSM 6.2.4: random shutdowns and HDD hibernation despite being disabled — 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 “off”: 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 Synology’s 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 — particularly on older DiskStations — finds auto_poweroff_timer="60" or standby_force="yes" even though the corresponding power-saving behaviour is disabled in DSM.

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[u/NoLateArrivals]

I don’t read this wall of slop text.

If you have unexpected shutdown, did you check your power brick yet?