Question for hdparm specialists

[gorzka]

I created a file in /etc/systemd/ system with the following content:

[Unit]
Description=Local system resume actions
After=suspend.target

[Service]
Type=simple
ExecStart=hdparm -S 120 /dev/disk/by-uuid/312cb74c-ee9e-4a50-adaa-677f2a61c50b

[Install]
WantedBy=suspend.target

Then did the following

systemctl enable...
systemctl start...
systemctl status...

and rebooted the computer. After 10 minutes it just doesn't happen. The plate doesn't turn off.

sudo systemctl status root-resume.service
[sudo] password for gorzka:
○ root-resume.service - Local system resume actions
Loaded: loaded (/etc/systemd/system/root-resume.service; enabled; preset: enabled)
Drop-In: /usr/lib64/systemd/system/service.d
└─10-timeout-abort.conf
Active: inactive (dead)​

Why is the process dead?

Of course I can use hd-idle, but I would like to find out why it doesn't work

[jlittle]

★ Does the command, run with sudo, have any effect? Ostensibly that applies a setting on the drive, and, perhaps naïvely, I would expect it to stick. Maybe hdparm -I should show the setting.

★ hdparm -S doesn't work for many drives. My desktop has a 2015 WD black and a very old Seagate Barracuda and hdparm -S does not work for either, IIRC. IIRC again, it did not work for any WD drives at the time I looked into it, but did for some Seagate models. If I use hdparm -S 120 on either the command appears to run, saying "setting standby to 120 (10 minutes)" but hdparm -I says "Standby timer values: spec'd by Standard, with device specific minimum" both before and after.

★ I don't understand why it's "WantedBy " "suspend.target". That applies when the system is going to sleep, or has come out of it.

★ "Active: inactive (dead)" just means the service is not running. This is what you want, you don't want it running for more than it takes to complete the command.

★ After changing systemd files anywhere, run systemctl daemon-reload or systemd might not notice.

★ If it was me, I'd separate getting the systemd stuff to work from the task at hand. As well, I'd always run a script that logs with timestamps that it's running and what it is doing.