UDEV rule - Disable SATA/SAS Disk Write Cache

Creating udev rule that disables disk write cache for specific drive models.

Requirements:

• sdparm utility

cat /etc/udev/rules.d/50-hgst.rules

ACTION=="add", SUBSYSTEM=="block", ATTRS{vendor}=="HGST", ATTRS{model}=="H7240AS60SUN4.0T", RUN+="/bin/sh -c '/usr/bin/sdparm -c wce /dev/%k'"

To find out various attribute names and values, run this command. Adjust device name.

udevadm info --attribute-walk --name /dev/sdk

Verify disk write cache state. Adjust device name.

sdparm --get wce /dev/sdk