I recently upgraded to 26.04 and I noticed three of my external hard drives are in standby mode, I tried the option Wake-Up from Standby in disks but nothing happened and when I tried it in terminal through the sudo hdparm -y command I received this error:
You should never operate on those device nodes (/dev/sd*) directly, because they can change from one boot to the next, so you might be talking to the wrong device. Best use the /dev/disk/by-* hierarchy which contains symbolic links to the real device, e.g:
points to /dev/sdb1 on my machine. There are other directories in /dev/disk but by-id tends to have somewhat easily recognizable names, that start with the interface, e.g. usb, and contain more identifying info.
Also hdparm -y is to force standby mode immediately and it seems you want to do the opposite. Simply accessing the device should wake it up.
Okay, thank you Peter! I will try what you’ve suggested. Thanks for your reply, I appreciate the advice! If anything comes up I’ll post back with the results.