[mythtv-users] 30 minute freezups

[Carl Fongheiser]

On Fri, Dec 19, 2008 at 11:19 AM, Greg Woods <greg at gregandeva.net> wrote:
> On Fri, 2008-12-19 at 18:04 +0100, Jan Ceuleers wrote:
>> Greg Woods wrote:
>> > Every 30 minutes, my system freezes hard for a couple of seconds. This
>> > results in a few seconds lost of every recording every half hour, and a
>> > few seconds pause in any recording I am watching.
>>
>> Do you use smartd?
>
> Yes! And I think this is a direct hit. From the smartd man page:
>
>  smartd  will attempt to enable SMART monitoring on ATA devices
>  (equivalent to smartctl -s on) and polls these and SCSI devices
>  every 30  minutes
>
> That's almost surely what it is. I would rather be able to spin the
> drives down when idle than have the SMART reporting (drive failure is
> extremely rare) so I'll turn off smartd and see if that fixes it.
> Thanks!
>
> I suspect the reason this happens to me is because I do have multiple
> drives that I store recordings on, so I can have a recording being made
> or watched, and still have the other drive spun down.
>

I think you're tilting at windmills here.  At least where I live, it
costs about 1 cent a day to let a hard drive spin at idle.
(Electricity runs about 6 cents/kilowatt-hour here.)  This is based on
a Seagate Barracuda 7200.11 drive, which draws about 8 watts at idle.
Even the previous generation 7200.10 drive draws less than 10 watts at
idle.  On the flip side, it can draw as much as 36 watts for up to 15
seconds when it needs to spin up.

You can do even better with something along the lines of a WD Caviar
Green drive, which draws less than 3 watts at idle.

I realize electricity is relatively cheap here in Iowa, but I'd
encourage you to do the math and  figure out if you're really saving
an appreciable amount of energy/money.  You're likely to do a lot
better trying to get your CPU to clock down when it's idle.  This is
especially true if you're using a processor like a Prescott Pentium 4.

Carl Fongheiser