Linux 7.2-rc6 Working Around Several Buggy Western Digital SATA Drives
This week's batch of ATA fixes end up force disabling Link Power Management (LPM) for several Western Digital drives that have not been functioning properly with the Linux kernel out-of-the-box due to power management behavior.
Since last year there was a kernel.org bug report over the SATA bus going offline after a while. On Linux kernels since last August, the user reported that their SATA drives were going offline. That issue was finally narrowed down to being the Link Power Management behavior on two of the drives in the system. LPM is supposed to be a power-saving feature for SATA devices to lower power use by resting the communication link between the HDD/SSD and the controller.
With Linux 7.2-rc6, the WDC WD100EFGX-68CPLN0 and WDC WD102KFBX-68M95N0 drives are now black-listed from using LPM by default so that they will behave correctly with the Linux kernel. The WD100EFGX-68CPLN0 is a 10TB Red Plus SATA HDD designed for NAS devices. The WD102KFBX-68M95N0 is Western Digital's 3.5-inch 10TB Red Plus Pro hard drive also catering to NAS use.
Another patch merged in this week's ATA queue is also disabling LPM for the Western Digital Green 2.5 480GB drive. That SATA drive was separately reported as having issues two to three minutes after booting Linux on the system with the device most typically disappearing until next reboot.
An alternative workaround for those not riding the latest kernel and using these drives is to boot the kernel with libata.force=nolpm to disable LPM -- or if you are wanting to test SATA troubles with different drives. But in disabling LPM you lose out on a reported 0.5~1.5W possible power saving per drive.
These workarounds are now merged for Linux 7.2-rc6 while the stable Linux 7.2 kernel will be out later in August.
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