Re: Weird hard disk noise on shutdown (bug #7674)

From: Robert Hancock
Date: Thu Feb 22 2007 - 01:31:58 EST

Robert Hancock wrote:
Alan wrote:
Stick some printk calls in drivers/ata/libata-eh.c in ata_eh_suspend, or
turn on all the ATA debug and shutdown, the code should issue a cache
flush followed by a standbynow1 command for each disk.


I believe it runs on suspend, but we don't run that code on normal shutdown, do we?

Tejun Heo had a patch for sd that could (optionally) trigger a START STOP UNIT command to spin the disk down after synchronizing the cache before shutdown, but I haven't heard anything of it lately..

And yes, this is something we need to deal with. I don't think that disks that use contact start-stop heads care so much, but disks that use load-unload heads (like most laptop drives, it seems) generally quote a much lower cycle lifetime for "emergency unloads" caused by power loss than by normal unloads done while power is still applied. It's important enough that in some cases, like the Compaq X1000-series laptop I have, the BIOS appears to have a power button handler that spins down the drive before power-down when the power button is pressed and an ACPI OS isn't running. (Holding the button down when an ACPI OS is running just forces the power off, then you get the clunk from the drive..)

Windows XP (and even as far back as Windows 98) get this right, surely we can do as well :-)

Robert Hancock Saskatoon, SK, Canada
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