Read this thread if you own a Western Digital "Green" HDD.

[Intersect444]

is this good external hard drive:

WESTERN DIGITAL WDBYVG0020BRD

[anon]

The issues with Western Digital's aggressive power management are all workable as long as you follow the advice in this thread. For an external disk, you'll have to use idle3ctl under Linux instead of WDIDLE3, since USB support for DOS is fickle and you may not even be able to boot it to begin with (modern motherboards no longer have BIOS interrupts or a compatibility module).

[anon]

I found this, but don't currently have an affected disk at hand, so feedback is welcome. openSeaChest is available for Linux and Windows and can be downloaded at https://github.com/Seagate/openSeaChest.

For Seagate drives with PowerChoice technology, tricks setting APM via hdparm will not work due to the EPC (Extended Power Conditions) feature. Rather than setting APM, you can install openseachestAUR and fully disable EPC like so (replace X with actual drive letter):

# openSeaChest_PowerControl --scan
# openSeaChest_PowerControl -d /dev/sdX -i
# openSeaChest_PowerControl -d /dev/sdX --showEPCSettings
# openSeaChest_PowerControl -d /dev/sdX --EPCfeature disable
# openSeaChest_PowerControl -d /dev/sdX --showEPCSettings

Last invocation will give the following summary:

==========================================================================================
 openSeaChest_PowerControl - openSeaChest drive utilities - NVMe Enabled
 Copyright (c) 2014-2023 Seagate Technology LLC and/or its Affiliates, All Rights Reserved
 openSeaChest_PowerControl Version: 3.3.1-4_1_1 X86_64
 Build Date: Jul  4 2023
 Today: Tue Jul  4 17:49:36 2023        User: root
==========================================================================================

/dev/sdX - ST1000NM0008-2F2100 - ZFA19JG2 - SN02 - ATA


===EPC Settings===
        * = timer is enabled
        C column = Changeable
        S column = Savable
        All times are in 100 milliseconds

Name       Current Timer Default Timer Saved Timer   Recovery Time C S
Idle A      0            *10           *10           1             Y Y
Idle B      0            *1200         *1200         3             Y Y
Idle C      0             6000          6000         16            Y Y
Standby Z   0             9000          9000         46            Y Y

Zeroes in the first column confirm that parking and spindown were disabled successfully