[HOW TO] Enable TLER/ERC/CCTL on Shucked Hard Drives

[MadPup]

For anyone out there like myself who is using shucked hard drives in their NAS, here is how you can configure error recovery control on drives that support it. Note that drive manufacturers refer to this feature as either TLER, ERC, or CCTL. Also note that the approach covered here re-enables the setting on each boot since, on my WD/HGST drives at least, I could not find a way to make the setting sticky across power cycles.

Disclaimer: I'm not advising on whether you should do this or not - that's up to you. There are lots of discussions elsewhere on the Internet on the whys of this topic.

Add the following script to your NAS startup:

#!/bin/sh
/usr/builtin/sbin/smartctl -d sat -l scterc,70,70 -i /dev/sda
/usr/builtin/sbin/smartctl -d sat -l scterc,70,70 -i /dev/sdb
/usr/builtin/sbin/smartctl -d sat -l scterc,70,70 -i /dev/sdc
/usr/builtin/sbin/smartctl -d sat -l scterc,70,70 -i /dev/sdd

In the above case I have 4 hard drives (in RAID10). If you have a different number of drives you should adjust the script appropriately.

See this forum article on how to run a script on system startup: https://forum.asustor.com/viewtopic.php?f=49&t=1681

After reboot you can verify that the changes have taken effect by entering the following command for each drive in your ssh terminal session:

sudo /usr/builtin/sbin/smartctl -d sat -l scterc -i /dev/sda

smartctl reference: https://linux.die.net/man/8/smartctl
scterc[,READTIME,WRITETIME] - [ATA only] prints values and descriptions of the SCT Error Recovery Control settings. These are equivalent to TLER (as used by Western Digital), CCTL (as used by Samsung and Hitachi) and ERC (as used by Seagate). READTIME and WRITETIME arguments (deciseconds) set the specified values. Values of 0 disable the feature, other values less than 65 are probably not supported. For RAID configurations, this is typically set to 70,70 deciseconds.