On Fri, Feb 10, 2012 at 11:21:04PM +0000, James Harper wrote:
I can see that this is a limitation without reason, but what use is reading the temperature of a sleeping drive? It would throw out all your averages.
i'm usually not interested in the average temp. i'm usually interested in the temp. right now and the trend over the last hour or so (i.e. how fast the temp. is rising)....to help decide whether to shut the system down or not on a hot summer day.
if the drive temps are significantly over about 40C and look like they're heading towards 50+C then i want to shut it down even if the drives are sleeping.
there's usually only a few days/year where it matters (and this summer has been good...i don't think we've had even one 40C day in Melbourne so far), but heat kills drives.
hddtemp will skip the temperature read if the drive is asleep unless you specify the '-w' option.
yep, but -w defeats the purpose of setting the drive's sleep timeout.
So... don't use the -w option, and hddtemp won't wake up the drives to ask them their temperature. Get your reading from another sensor if that happens, eg: temp=`hddtemp /dev/sdn || get_mb_temp` An asleep drive isn't going to overheat. Would it be fair to assume that you are also monitoring the CPU temperature? That's probably another good candidate for detecting an overtemperature condition that requires a shutdown. It is a little puzzling as to why an ATA drive needs to be spun up to take a temperature reading though... maybe the sensor is inside the enclosure and requires some airflow to ensure an accurate reading? James