cswiger at mac.com
Fri Nov 13 21:21:43 UTC 2009
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.
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