Date: Wed, 4 Mar 2009 14:50:45 -0600 From: Octavian Covalschi <octavian.covalschi@gmail.com> To: freebsd-hackers@freebsd.org, octavian.covalschi@gmail.com Subject: Re: Spin down HDD after disk sync or before power off Message-ID: <c0f49ea0903041250l252f16ads25b735b7bf4c533c@mail.gmail.com> In-Reply-To: <200903041938.n24Jcqdr060153@lurza.secnetix.de> References: <c0f49ea0903040910w496f4a72m3c3ce6882e55c307@mail.gmail.com> <200903041938.n24Jcqdr060153@lurza.secnetix.de>
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Thank you for detailed and clear answer! On Wed, Mar 4, 2009 at 1:38 PM, Oliver Fromme <olli@lurza.secnetix.de>wrote= : > Octavian Covalschi wrote: > > I'm looking a way to spin down HDD just right before power off. Why? > > > > Because currently when I call "shutdown -p now", HDD is powered off at > it's > > full speed (7200.4) and as a result > > I hear a noise of stopping/spinning down of HDD, and _this_ concerns m= e > as > > I'm afraid it can damage HDD. > > You don't have to spin down a disk before powering it off. > The noise you hear is probably caused by the "autopark" > feature of the drive. It is harmless. > > > I've tried to use rc.shutdown, but the sync of disks "wakes" HDD > again... > > Of course, upon halt or reboot the kernel will sync all > file systems that have been mounted read+write. > > > While searching for a solution, I noticed that reboot command/app _doe= s_ > > spin down hdd right before it resets system power, > > I can hear how HDD is powered on after that... > > No, the reboot command doesn't do that. It's probably your > BIOS that resets the devices. > > > 2nd thing is I cannot find "halt.c" file, i wanted to take a look how = it > > does it... although I'm up to date it's not not in > > /usr/src/sbin > > halt(8) is a hardlink to reboot(8). > Look at src/sbin/reboot. > > By the way, the syncing does not happen in halt(8). At the > time the kernel syncs the disks, no processes are running > anymore, not even init(8). You can't do anything from > userland at this point. If you want to insert a spin-down > for your disks, you will have to modify the kernel. You > have to install an event handler for "shutdown_post_sync". > See the boot() function in src/sys/kern/kern_shutdown.c > for details about the kernel's shutdown sequence. > > Best regards > Oliver > > -- > Oliver Fromme, secnetix GmbH & Co. KG, Marktplatz 29, 85567 Grafing b. M. > Handelsregister: Registergericht Muenchen, HRA 74606, Gesch=E4ftsfuehrun= g: > secnetix Verwaltungsgesellsch. mbH, Handelsregister: Registergericht M=FC= n- > chen, HRB 125758, Gesch=E4ftsf=FChrer: Maik Bachmann, Olaf Erb, Ralf Geb= hart > > FreeBSD-Dienstleistungen, -Produkte und mehr: http://www.secnetix.de/bsd > > "Python is an experiment in how much freedom programmers need. > Too much freedom and nobody can read another's code; too little > and expressiveness is endangered." > -- Guido van Rossum >
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