Date: Fri, 13 Nov 2009 12:15:53 -0800 (PST) From: James Phillips <anti_spam256@yahoo.ca> To: freebsd-questions@freebsd.org Subject: Re: APM Message-ID: <474730.92984.qm@web65506.mail.ac4.yahoo.com> In-Reply-To: <20091113120016.DDE941065720@hub.freebsd.org>
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> Date: Thu, 12 Nov 2009 10:28:10 -0800 (PST) > From: James Phillips <anti_spam256@yahoo.ca> > Subject: APM > To: freebsd-questions@freebsd.org > Message-ID: <784120.47330.qm@web65508.mail.ac4.yahoo.com> > Content-Type: text/plain; charset=us-ascii > <SNIP!> > > I realize the memory can't be shutdown without Hibernation > support, but the disks can be spun down manually (using > atacontrol): > http://forums.freebsd.org/showthread.php?t=1012 > > However, when I try to do that, I find that the disk wakes > within 2 seconds of spinning down. I noticed that the > spindowns are logged. Could the log being written be causing > the drive to spin up again? <SNIP!> I initially set the time-out to 60 seconds, then 300 seconds in a vain attempt to see the actual power savings. With a 900 second time-out, the drive only spun down once in the past 12 hours. It appears that syslogd can defer *one* log entry. Understandable, since you don't want to loose too many logs in a power failure. tail /var/log/messages (trimmed entries from the 300 second time-out): Nov 13 07:46:59 dusty kernel: ad4: Idle, spin down Nov 13 07:46:59 dusty kernel: wakeup from sleeping state (slept 00:35:44) Nov 13 07:47:01 ad4: request while spun down, starting. It looks like the logging of the "spin down" woke up the sleeping system. Either that, or the computer did not know the actual spin-down time. The sleep time was reported to be 2144 seconds: 1244 seconds longer than the the set spin-down time (900 seconds). If it was spun-down when I checked this morning, the difference was less than 3W. Though, the current drive (5400RPM) uses ~2 fewer watts than the old (7200 RPM) drive. I'm an not sure, since I replaced RAM, and installed an optical drive since measuring my base-line (with the old drive). My computer case has noise-dampening foam for the hard-disk. I can't hear if the drive is spinning over the inverter in the ADSL modem (9W) and the (quiet) fan noise from both the router (21W) and server. I can heard a "click" when it starts up, that is about it. Regards, James Phillips __________________________________________________________________ Yahoo! Canada Toolbar: Search from anywhere on the web, and bookmark your favourite sites. Download it now http://ca.toolbar.yahoo.com.
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