Sleep usb sleep

[snakekick]

Hello,

i have a litte problem with my armbian/helios.

I use a usb hdd for "backup" (snapraid parity) that only need to run every 2 days so that i unmount the drive and put this in standby (hdparm -y /dev)

All goes well but after some time the drive awake again (without mount) and i dont know how i can prefent this.

does anyone have an idea where I can look

thanks for help.

 

 

 

 

[djurny]

Hi @snakekick,

USB HDD for snapraid parity, sounds like my setup! You can check with vm_block_dump what is waking up your device: 

 

echo 1 | sudo tee /proc/sys/vm/block_dump

Above will enable logging of block device accesses into syslog.

 

If you want to see it happen without flooding your /var/log/syslog:

sudo service rsyslog stop
while true ; do dmesg -cT ; done
sudo service rsyslog start

 

See: Documentation for /proc/sys/vm/* and How to conserve battery power using laptop-mode.

 

You should also check if you have enabled SMART offline auto testing on your HDD; that might also wake up your drive, but this is done by the drive itself:

sudo smartctl -a /dev/sdX | egrep 'offline'
sudo smartctl --offlineauto=off /dev/sdX

 

Other things that will wake up your drive: temperature monitoring services like hddtemp, you should check if it offers options to not access the drive if it's in standby/sleep mode.  Other things like blkid when used as root, will also check all blockdevices, even if you think it is using cache.

 

What is the brand of USB dock you are using? Perhaps your dock is doing something to the drive to wake it up regularly.

 

Hope that helps,

Groetjes,