Date: Fri, 13 Nov 2009 13:21:42 -0800 From: Chuck Swiger <cswiger@mac.com> To: James Phillips <anti_spam256@yahoo.ca> Cc: freebsd-questions@freebsd.org Subject: Re: APM Message-ID: <E7630082-8284-45A3-AF72-7C3DB2BBB9DA@mac.com> In-Reply-To: <474730.92984.qm@web65506.mail.ac4.yahoo.com> References: <474730.92984.qm@web65506.mail.ac4.yahoo.com>
next in thread | previous in thread | raw e-mail | index | archive | help
Hi-- On Nov 13, 2009, at 12:15 PM, James Phillips wrote: > 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. One of the first things you should consider is either disabling syslogd entirely, or else setup logging to a RAMdisk (ie, have an initial copy of what's in /var on the hard disk, setup a RAMdisk and mount as /var, then copy over the /var tree from hard drive to RAMdisk during early stages of system boot). The advice given for NanoBSD or embedded NetBSD systems about conserving writes to a flash-based filesystem would be helpful in your case. You might also want to note that 2.5" laptop drives are/should be explicitly designed to spin down and park themselves much more often than generic IDE drives are; some generic desktop drives will fail quite rapidly (ie, in a matter of months) if you attempt to spin them down many times a day. You might also give some consideration to trying a Mac Mini with maximum power-savings mode enabled; OSX provides significant amounts of hysteresis to avoid spinning the disks up and down, and will buffer significant amounts of data being changed into RAM to coalesce filesystem activity into fewer periods of disk activity. Regards, -- -Chuck
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?E7630082-8284-45A3-AF72-7C3DB2BBB9DA>