[vdr] Re: 18 Minutes - what does that tell?

[Emil Naepflein <Emil.Naepflein@philosys.de>]

> It' not about lifetime. 

If your disks die because of this and you loose recordings I am sure you
will thik different next time. ;-)

> That is of minor importance. It's about having a quiet SetTopBox.

Current disks are already very quiet and you can do additional things
with your case.

> Using nfs would help, but you will certainly not be able to take the box to a friend of yours then.

Taking a STB to some other place is certainly not the normal case.

> I used noflushd quite some time. 100 cycles a day is far too high a value. 

Read the subject, and see what may happen if you don't watch that
closely.

> It's somewhere around 10, sometimes 20 cycles a day 
> (depends on what else is running on your system). 
> So 10-20 cycles a day makes appx. 7-13 years.

If someone does a lot of recordings and playbacks then 10-20 times is
not much. But it also depends on the stop timeout you have programmed
for the disk. If it is only 1 minute I am pretty sure that even *normal*
use will cause much more spinups. If you have a timeout of 30 minutes it
will be much less. This has certainly to be watched and tuned.

> But running the HDD 24/7 will reach 80000 hours in about 9 years 
> (I don't know the exact value for MTBF for Maxtor). But it consumes 
> a lot more power (that I don't mind that much) and produces quiet 
> some heat (that _IS_ a real problem if your box is supposed to be 
> quiet, i.e. having no fans.

That is a point, but you have to remove the heat anyway in case the
system is used for more than a few minutes. And if this works ok it will
work also for the 24/7 case. Disks are very sensible to heat. 

> 
> So I think it's a matter of personal opinion.

May be. I am running a VDR server 24/7 in the basement, so all your
arguments are not relevant for me. And I have experience with HDs for
more than 20 years and have seen many disks die during start/stop cycles
and disks running in 24/7 case a considerable factor longer than the
specified MTBF. Start/stop causes wear in electronics and mechanic
components.

The other point I would like to mention is the data loss you will
experience if the system crashes for some reason or there is a power
outage. If you have lost several of your recordings thru inconsistencies
in the filesystem I think you will think a bit different.

But of course, it's your choice.

Emil

PS: Please cut your lines to 72 characters.